ZIMDART TD

Indications

• Skin disinfection
• Preparation of skin before injections
• Cleansing minor wounds

Dosage

Children: Apply to the skin as required; consult product literature for specific guidance.

Adults: Apply to the skin as required for disinfection.

Mechanism of action

Alcohol exerts its antiseptic effect by denaturing proteins, disrupting cell membranes, and dehydrating microbial cells, leading to cell lysis and death.

Pharmacodynamics

Alcohol has broad-spectrum antimicrobial activity, effective against bacteria, fungi, and viruses. Its efficacy is influenced by concentration, with higher concentrations generally being more effective.

Pharmacokinetics

Alcohol is rapidly absorbed through the skin and mucous membranes. It is metabolized primarily in the liver, with a half-life that varies based on the individual's metabolic rate and the amount consumed.

Contra-indications

• Concomitant use with lithium
• Regular use in neonates
• Patients with severe burns when diathermy has been preceded by application of alcoholic skin disinfectants

Adverse effects

• Eye erythema
• Punctate keratitis
• Cytotoxicity
• Eye discolouration

Interactions

• Increases risk of visual disturbances with antiepileptics
• Increases concentration with methylphenidate
• Increases risk of facial flushing and skin irritation with topical pimecrolimus
• Increases concentration with retinoids
• Increases concentration with acitretin
• Increases risk of facial flushing and skin irritation with topical tacrolimus
• Decreases antidiuretic effect with vasopressin

Precautions

• Avoid regular application to inflamed or broken skin or mucosa
• Avoid broken skin
• Flammable

Pregnancy

Sufficient iodine may be absorbed to affect the fetal thyroid in the second and third trimester.

Breast-feeding

Avoid regular or excessive use.

Storage

Store in a cool, dry place away from heat and direct sunlight.

Formulations

• Betadine 2.5% dry powder spray
• Industrial methylated spirit
• Povidone-Iodine 25 mg per 1 gram

Indications

• Low blood volume
• Hypovolemic shock
• Burns
• Cardiopulmonary bypass

Dosage

Children: Initially 10-20 mL per kilogram. Adjust according to the patient's condition and response, using 3.5-4% solution. Use under specialist supervision to mitigate the risk of fluid overload.

Adults: Dose according to requirements, typically administered intravenously. Consult product literature for specific dosing guidance.

Mechanism of action

Gelatin acts as a plasma expander by increasing the oncotic pressure in the vascular compartment, which helps to retain fluid within the bloodstream and restore circulating blood volume. This mechanism aids in maintaining blood pressure and improving tissue perfusion.

Pharmacodynamics

Gelatin solutions increase blood volume and improve hemodynamic stability in patients experiencing hypovolemic conditions. By drawing water into the vascular space, they help to counteract the effects of low blood volume, such as hypotension and compromised organ perfusion.

Pharmacokinetics

Gelatin is administered intravenously, and its effects can be observed relatively quickly. The half-life and the metabolic clearance depend on the formulation and concentration of the solution. Gelatin is gradually metabolized by macrophages and eliminated by the renal system. Close monitoring of fluid balance is essential, particularly in patients with cardiac or renal impairment.

Contra-indications

• Severe liver disease
• History of circulatory disease
• Severe cardiac disease

Adverse effects

• Fever
• Flushing
• Nausea
• Urticaria
• Rare or very rare shock

Interactions

• Calcium salts

Precautions

• Monitor cardiovascular and respiratory function
• Correct dehydration when administering
• Administer slowly to avoid rapid rise in blood pressure and cardiac failure
• Increased capillary permeability

Pregnancy

Consult product literature for specific guidance regarding use in pregnancy.

Breast-feeding

Consult product literature for specific guidance regarding use in breastfeeding.

Storage

Store at controlled room temperature, protect from light. Refer to product-specific storage instructions.

Formulations

• 5% solution for infusion
• 20% solution for infusion
• Concentrated solution (15-25% protein)
• Isotonic solution (3.5-5% protein)

Indications

• Benign prostatic hyperplasia
• Bladder outlet obstruction
• Urinary retention

Dosage

Children: Not established; refer to BNF for Children for any potential dosing information.

Adults: Initially 400 micrograms once daily, taken after a meal. Dosage may be adjusted based on clinical response and tolerability, typically not exceeding 800 micrograms daily.

Mechanism of action

Tamsulosin exerts its therapeutic effects through selective antagonism of the alpha-1A adrenergic receptors found predominantly in the smooth muscle of the prostate and bladder neck. This action results in relaxation of these muscles, leading to improved urinary flow and reduced bladder outlet obstruction.

Pharmacodynamics

The pharmacodynamics of Tamsulosin involve its ability to decrease urinary resistance and improve urinary flow rates. It exhibits a preferential binding affinity for the alpha-1A receptors compared to alpha-1B receptors, which minimizes cardiovascular side effects commonly associated with non-selective alpha blockers. The onset of action typically occurs within a few days of starting treatment, although maximum benefits may take several weeks.

Pharmacokinetics

Tamsulosin is well-absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 6 hours post-administration. It has a bioavailability of about 90% due to extensive first-pass metabolism. The drug is primarily metabolized in the liver via CYP2D6 and CYP3A4 pathways, resulting in several active metabolites. Tamsulosin has a half-life of approximately 15 hours, allowing for once-daily dosing. It is excreted mainly in urine as metabolites, with less than 10% of the drug eliminated unchanged.

Contra-indications

• History of micturition syncope
• History of postural hypotension
• Congestive heart failure (due to mechanical obstruction such as aortic stenosis)

Adverse effects

• Asthenia
• Dizziness
• Constipation
• Fatigue
• Sweating

Interactions

• Caution with concomitant antihypertensives
• Potential for additive hypotensive effects when used with other antihypertensives

Precautions

• Caution in elderly patients due to risk of first dose hypotension
• Care during cataract surgery due to risk of intra-operative floppy iris syndrome
• Monitor for symptomatic orthostatic hypotension

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Use only if clearly needed.

Breast-feeding

It is not known whether tamsulosin is excreted in human milk. Caution is advised when administering to breastfeeding mothers.

Storage

Store below 25 degrees Celsius. Keep the container tightly closed.

Formulations

• Tamsulosin hydrochloride 400 microgram capsules
• Tamsulosin hydrochloride 500 microgram tablets
• Tamsulosin hydrochloride modified-release capsules

Indications

• Benign prostatic hyperplasia

Dosage

Adults: 500 micrograms daily, with treatment review at 3–6 months and then every 6–12 months.

Mechanism of action

Dutasteride binds to both type I and type II isoenzymes of 5α-reductase, forming a stable complex that inhibits the conversion of testosterone to DHT. DHT is a key hormone in prostate development and growth, and by reducing its levels by more than 90%, dutasteride alleviates symptoms of BPH and improves urinary flow.

Pharmacodynamics

Dutasteride exhibits a dose-dependent reduction in circulating DHT levels, with maximum effects observed within 1-2 weeks after initial administration. Clinical studies have shown that median serum DHT concentrations were reduced by 85% and 90% after 1 and 2 weeks of daily dosing with 0.5 mg, respectively. Continuous administration of dutasteride maintains DHT levels suppressed in the majority of patients, and it may also lead to decreased serum prostate-specific antigen (PSA) levels in patients with prostate cancer.

Pharmacokinetics

Dutasteride is well absorbed after oral administration, with a peak plasma concentration typically reached within 1-2 hours. The drug has a long half-life, allowing for once-daily dosing. It is extensively metabolized in the liver, primarily by CYP3A4 and CYP3A5 enzymes, leading to the formation of several metabolites. The elimination half-life is approximately 5 weeks, which supports the need for regular follow-up and dose adjustment based on clinical response.

Contra-indications

• History of micturition syncope
• History of postural hypotension

Adverse effects

• Abdominal pain
• Anxiety
• Angioedema
• Arrhythmias
• Asthenia
• Chest pain
• Constipation
• Cough
• Depression
• Dizziness
• Diarrhoea
• Drowsiness
• Fatigue
• Gastrointestinal disturbances
• Hyperhidrosis
• Insomnia
• Myalgia
• Nasal congestion
• Nausea
• Oedema
• Palpitations
• Paraesthesia
• Postural hypotension
• Sexual dysfunction
• Skin reactions
• Syncope
• Vomiting
• Weight gain

Interactions

• Cobicistat increases exposure
• Idelalisib increases exposure
• Clarithromycin increases exposure
• Crizotinib unknown effect on exposure
• Imatinib unknown effect on exposure
• Letermovir unknown effect on exposure
• Nilotinib unknown effect on exposure
• Terazosin may increase risk of hypotension

Precautions

• Caution in elderly patients
• Caution in patients with history of prostate cancer
• Monitor for signs of hypotension and syncope
• Consider lower initial dose in patients with autonomic neuropathy

Pregnancy

Dutasteride is contraindicated in pregnancy due to potential harm to a male fetus.

Breast-feeding

Manufacturer advises avoiding use during breastfeeding due to potential for effects on the infant.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Dutasteride 0.5 mg capsules

Dosage

Children: Refer to specific guidelines or consult the BNF for appropriate dosage.

Adults: Refer to specific guidelines or consult the BNF for appropriate dosage.

Mechanism of action

Acrylate acts as a reactive compound that can participate in various biochemical reactions. It may undergo conjugation with glutathione and other biomolecules, leading to detoxification or metabolic transformation. The involvement of acrylate in the metabolism of seleno-compounds suggests a role in the detoxification pathways, where it may facilitate the elimination of harmful substances from the body.

Pharmacodynamics

Acrylate does not have established pharmacodynamic effects as a therapeutic agent, as it is primarily recognized for its industrial applications. However, its interactions with biological macromolecules can lead to cytotoxic effects, especially at high concentrations. It is known to be a skin and respiratory irritant, and prolonged exposure may result in a range of toxicological effects.

Pharmacokinetics

The pharmacokinetics of acrylate in humans have not been extensively studied, but it is known to be rapidly absorbed through the skin and respiratory tract. Once in the body, acrylate can undergo biotransformation primarily through conjugation with glutathione, leading to more water-soluble metabolites that can be excreted via urine. The compound's half-life and distribution in human tissues are not well-characterized.

Pregnancy

The safety of acrylate during pregnancy has not been fully established. It is advisable to avoid use unless deemed absolutely necessary by a healthcare professional.

Breast-feeding

Limited data exist on the use of acrylate during breastfeeding. Caution is advised, and it should only be used if the benefits outweigh potential risks.

Storage

Store in a cool, dry place away from direct light and moisture. Keep out of reach of children.

Dosage

Children: Refer to specific formulations and usages, as dosing can vary widely depending on the application and regulatory guidelines.

Adults: Refer to specific formulations and usages, as dosing can vary widely depending on the application and regulatory guidelines.

Mechanism of action

Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) act as antioxidants by inhibiting the oxidation of lipids. They scavenge free radicals and donate hydrogen atoms to reactive species, thus stabilizing and preventing oxidative damage to cellular components. This action helps to protect the integrity of cell membranes and prevent the formation of harmful peroxides.

Pharmacodynamics

The pharmacodynamic properties of butylated compounds are primarily related to their antioxidant activity. They exhibit a dose-dependent ability to inhibit lipid peroxidation, which is crucial in protecting cells from oxidative stress. Furthermore, they may modulate certain biochemical pathways involved in cell signaling and apoptosis, although these effects are less well-characterized.

Pharmacokinetics

Butylated compounds are absorbed from the gastrointestinal tract following oral ingestion. They undergo metabolic processing primarily in the liver, where they are conjugated and excreted in urine. The half-life of butylated compounds in humans is variable, influenced by factors such as dosage and individual metabolism. Accumulation in tissues is generally low, but prolonged exposure may lead to higher tissue concentrations.

Adverse effects

• Gastrointestinal disturbances
• Allergic reactions
• Potential carcinogenic effects with prolonged exposure

Precautions

• Use with caution in patients with a history of hypersensitivity to butylated compounds
• Avoid prolonged exposure due to potential toxicity

Pregnancy

Limited data available, use only if the benefits outweigh the risks.

Breast-feeding

Unknown, exercise caution and consult a healthcare provider.

Storage

Store in a cool, dry place away from light.

Formulations

• Butylated hydroxytoluene (BHT)
• Butylated hydroxyanisole (BHA)

Indications

• Constipation
• Labor induction
• Topical treatment for skin conditions

Dosage

Children: Refer to the BNF for Children for appropriate pediatric dosing guidelines, as no specific doses are provided.

Adults: Refer to specific guidelines for adult dosing based on the formulation used and the condition being treated, as no standardized dose is provided.

Mechanism of action

Ricinoleic acid, the main active component of castor oil, acts as a stimulant laxative. It works by increasing the peristaltic movement of the intestines, which aids in the evacuation of stool. Additionally, it may inhibit the absorption of water in the intestines, resulting in softer stools. The oil is also believed to have anti-inflammatory properties, which can be beneficial in treating certain skin conditions.

Pharmacodynamics

The pharmacodynamic properties of castor oil include its ability to stimulate intestinal motility and increase the secretion of intestinal fluids. This leads to a faster transit time for stool through the bowel. In topical applications, castor oil exhibits emollient and moisturizing effects, promoting healing and soothing irritated skin. Its anti-inflammatory effects may also contribute to the reduction of swelling and pain in inflamed tissues.

Pharmacokinetics

Castor oil is absorbed in the gastrointestinal tract, where it is metabolized to ricinoleic acid. The onset of action for its laxative effect typically occurs within 2 to 6 hours after oral administration. The duration of action varies, but effects usually last for several hours. When applied topically, castor oil penetrates the skin and may provide localized effects without significant systemic absorption.

Adverse effects

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting
• Dehydration

Precautions

• Use with caution in patients with gastrointestinal disorders
• Not recommended for prolonged use
• Monitor for signs of dehydration

Pregnancy

Castor oil is generally not recommended during pregnancy due to potential uterine contractions and risk of premature labor.

Breast-feeding

Castor oil should be used with caution during breastfeeding as it may cause gastrointestinal discomfort in nursing infants.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Liquid
• Capsules

Indications

• Constipation
• Dietary fiber supplementation
• Irritable bowel syndrome
• Diverticular disease
• Weight management

Dosage

Children: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Adults: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Mechanism of action

Cellulose acts primarily as a bulk-forming laxative. It absorbs water in the intestines, which increases stool bulk and stimulates peristalsis, thus facilitating bowel movements. Additionally, cellulose is not digestible by human enzymes, leading to fermentation by gut bacteria, which may enhance gut health and alter gut microbiota composition.

Pharmacodynamics

Cellulose increases stool weight and frequency of bowel movements. It works by retaining water in the intestines, leading to softer stools and improved passage through the gastrointestinal tract. The bulking effect of cellulose can help alleviate constipation and promote overall digestive health. It may also play a role in cholesterol reduction and glycemic control through its effects on digestion and absorption of nutrients.

Pharmacokinetics

Cellulose is not absorbed into the bloodstream due to its indigestible nature. Instead, it passes through the gastrointestinal tract, where it adds bulk to the stool. Its fermentation by colonic bacteria produces short-chain fatty acids, which may have beneficial effects on colon health. The onset of action for cellulose as a laxative can vary but is generally within 24 to 72 hours after ingestion.

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for potential allergic reactions in sensitive individuals.

Pregnancy

Cellulose is generally considered safe during pregnancy as it is a non-toxic, indigestible fiber.

Breast-feeding

Cellulose is also considered safe during breastfeeding; it is excreted in breast milk in negligible amounts.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Powder
• Capsules
• Tablets
• Granules

Dosage

Children: Refer to specific drug guidelines for paediatric dosing.

Adults: Refer to specific drug guidelines for adult dosing.

Pregnancy

The safety of chain during pregnancy has not been established. It should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is unknown whether chain is excreted in human milk. Caution should be exercised when administering to breastfeeding women.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Indications

• Drug delivery systems
• Biodegradable implants
• Controlled release formulations
• Tissue engineering
• Medical device coatings

Dosage

Children: As with adult dosing, paediatric dosing of copolymers is specific to the formulation and application. Consult relevant pediatric pharmacology resources for detailed dosing recommendations.

Adults: Dosing of copolymers is highly variable and dependent on the specific drug formulation and intended use. For precise dosing information, refer to established pharmacological guidelines or product-specific resources.

Mechanism of action

Copolymers can function as drug delivery vehicles, allowing for controlled release of therapeutic agents. They can encapsulate drugs and release them in a sustained manner, depending on environmental triggers such as pH or temperature. This mechanism enhances the efficacy of drugs while minimizing side effects.

Pharmacodynamics

The pharmacodynamic properties of copolymers depend on their composition and structure, influencing their interaction with biological systems. They can modify drug release profiles and enhance the therapeutic effects of co-administered agents, facilitating targeted delivery to specific tissues or cells.

Pharmacokinetics

The pharmacokinetics of copolymers vary based on their molecular weight, structure, and the drugs they carry. Factors such as absorption, distribution, metabolism, and excretion will depend on the formulation and the specific application. Generally, copolymers can improve drug stability and prolong circulation time in the body.

Pregnancy

The safety of copolymer use during pregnancy has not been established. Non-essential use should be avoided.

Breast-feeding

The excretion of copolymers in human milk is unknown. Caution is advised when administering to nursing mothers.

Storage

Store in a cool, dry place away from direct light. Check specific product storage requirements as they may vary.

Indications

• Monitoring respiratory function
• Assessment of metabolic status
• Management of respiratory acidosis
• Management of respiratory alkalosis

Dosage

Children: Dosing for interventions related to carbon dioxide levels in pediatric patients should be guided by clinical protocols and the BNF for Children.

Adults: Dosing for interventions related to carbon dioxide levels is typically based on clinical assessment and individual patient needs. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Carbon dioxide acts primarily as a signaling molecule in the body, influencing respiratory drive and blood pH. It is produced during cellular respiration and is a critical component of the bicarbonate buffering system, which helps maintain acid-base homeostasis. Elevated levels of CO2 in the blood stimulate ventilation in the lungs, increasing the rate of gas exchange and facilitating the removal of excess CO2.

Pharmacodynamics

The pharmacodynamic effects of dioxides, particularly carbon dioxide, are closely related to its concentration in the blood. As CO2 levels increase, it leads to respiratory acidosis, which can stimulate the respiratory centers in the brain to increase ventilation. Conversely, low levels of CO2 can cause respiratory alkalosis, potentially leading to decreased respiratory drive. CO2 also plays a role in vasodilation and can affect blood flow and pressure through its influence on smooth muscle tone.

Pharmacokinetics

Carbon dioxide is produced endogenously during metabolic processes and is transported in the bloodstream primarily in three forms: dissolved in plasma, as bicarbonate ions (HCO3-), and bound to hemoglobin. The half-life of CO2 in the bloodstream is very short due to its rapid exchange with alveolar gas in the lungs. The elimination of CO2 occurs through exhalation, making it a dynamic component of respiratory physiology.

Pregnancy

Data on the effects of dioxide during pregnancy are limited. Caution is advised due to potential risks associated with exposure.

Breast-feeding

Limited data are available regarding the excretion of dioxide in human milk. Caution is recommended.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Indications

• Oral medications for improved solubility
• Topical applications for enhanced delivery of active ingredients
• Parenteral formulations for intravenous administration
• Vaccines delivered as emulsions for enhanced immune response

Dosage

Children: Refer to specific product information for dosage guidelines, as this varies by formulation and intended use.

Adults: Refer to specific product information for dosage guidelines, as this varies by formulation and intended use.

Mechanism of action

The mechanism of action of a dispersion often involves the physical distribution of active pharmaceutical ingredients in a medium, which can lead to increased surface area and improved interaction with biological membranes. For example, in emulsions, the dispersion of oil in water can enhance the absorption of lipid-soluble drugs.

Pharmacodynamics

Pharmacodynamics of dispersions relates to how the dispersed formulation affects the body. The presence of surfactants or emulsifying agents can modify drug release rates, enhance absorption, and improve therapeutic effects. The effectiveness of a dispersion is influenced by particle size, viscosity, and the nature of the dispersing medium.

Pharmacokinetics

The pharmacokinetics of dispersions depend on the formulation type and the route of administration. Key factors include the rate of dispersion breakdown, absorption through biological membranes, distribution within the body, metabolism, and excretion of the active ingredients. Dispersions can alter the onset of action and duration of effect based on their formulation characteristics.

Pregnancy

Consult with a healthcare provider before use. Safety in pregnancy is not established for all formulations.

Breast-feeding

Consult with a healthcare provider before use. Safety during breastfeeding may vary depending on the formulation.

Storage

Store in a cool, dry place away from direct sunlight. Follow specific storage instructions provided by the manufacturer.

Indications

• Chronic hepatitis C virus infection
• Genotype 1 HCV infection

Dosage

Children: Refer to BNF for Children for specific dosing information tailored to paediatric patients.

Adults: Refer to BNF for specific dosing information based on the clinical scenario.

Mechanism of action

Paritaprevir inhibits the NS3/4A serine protease of the Hepatitis C Virus (HCV). This enzyme is responsible for cleaving the viral polypeptide into essential structural and nonstructural proteins necessary for the assembly of mature virus. By inhibiting NS3/4A, paritaprevir prevents viral replication and function.

Pharmacodynamics

At concentrations significantly above therapeutic levels, paritaprevir and its combination with ombitasvir do not prolong the QTc interval to a clinically relevant extent. This suggests a favorable safety profile concerning cardiac effects at therapeutic doses.

Pharmacokinetics

Paritaprevir is absorbed effectively after oral administration, with its pharmacokinetic profile characterized by a peak plasma concentration occurring within a few hours post-dose. It is extensively metabolized in the liver, primarily via CYP3A4, and is eliminated mainly through fecal excretion. The half-life of paritaprevir allows for once-daily dosing when used in combination therapies.

Pregnancy

The safety of paritaprevir in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is unknown if paritaprevir is excreted in human milk. Caution is advised when administered to breastfeeding women.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Indications

• Alcohol use disorder
• Anxiety disorders
• Sedation
• Muscle relaxation

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines in paediatric populations.

Adults: Refer to the specific BNF guidelines for dosing related to alcohol use disorder and other indications.

Mechanism of action

Ethyl groups serve primarily as substituents in organic chemistry, influencing the properties and reactivity of the parent molecules. In the context of ethanol, which contains an ethyl group, its mechanism of action involves the enhancement of gamma-aminobutyric acid (GABA) receptor activity, leading to increased inhibitory neurotransmission. This results in its sedative, anxiolytic, and muscle relaxant effects.

Pharmacodynamics

The pharmacodynamics of compounds containing the ethyl group, particularly ethanol, include its effects on the central nervous system, where it acts as a depressant. Ethanol enhances the effects of GABA, resulting in sedation, impaired motor function, and decreased anxiety. It can also affect the dopaminergic pathways, leading to the release of dopamine, which contributes to its reinforcing properties.

Pharmacokinetics

Ethanol is rapidly absorbed from the gastrointestinal tract, with peak blood concentrations typically reached within 30 to 90 minutes after consumption. It is metabolized primarily in the liver by alcohol dehydrogenase and aldehyde dehydrogenase, with a first-order elimination kinetics, typically at a rate of 10 to 15 mL of pure alcohol per hour. Ethanol is also known to exhibit a volume of distribution of approximately 0.5 to 0.7 L/kg in adults.

Indications

• Antioxidant support
• Anti-inflammatory treatment
• Antimicrobial activity
• Potential adjunct in cancer therapy

Dosage

Children: Refer to specific guidelines or literature for appropriate dosing as it may vary based on the formulation and intended use.

Adults: Refer to specific guidelines or literature for appropriate dosing as it may vary based on the formulation and intended use.

Mechanism of action

Gallate exerts its effects primarily through its antioxidant properties, scavenging free radicals and reducing oxidative stress. It may also modulate various signaling pathways involved in inflammation and cell survival, contributing to its potential therapeutic effects.

Pharmacodynamics

The pharmacodynamics of gallate involve its ability to inhibit lipid peroxidation and protect cellular components from oxidative damage. It may also influence enzymatic activities related to metabolic pathways, enhancing the degradation of glutamate and other compounds. Gallate’s interaction with cellular receptors can lead to downstream effects such as reduced inflammation and altered apoptotic processes.

Pharmacokinetics

Gallate is absorbed in the gastrointestinal tract and undergoes metabolism primarily in the liver. Its bioavailability can be affected by food intake and formulation. The elimination half-life and specific excretion pathways are not well-documented, but it is expected to follow typical patterns for phenolic compounds, with renal excretion of metabolites.

Pregnancy

There is insufficient data on the safety of gallate during pregnancy. It is advisable to avoid use unless potential benefits outweigh risks.

Breast-feeding

Limited data available on the excretion of gallate in human milk. Caution is advised when administering to breastfeeding mothers.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Dosage

Children: Refer to the BNF for Children for appropriate dosing information in paediatric cases, especially in instances of overdose.

Adults: Refer to the BNF for specific dosing information based on clinical circumstances, particularly in cases of overdose.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is subsequently converted to glycolic, glyoxylic, and oxalic acids. These metabolites contribute to anion gap metabolic acidosis and are responsible for tissue injury through the formation of insoluble calcium oxalate crystals.

Pharmacodynamics

The toxicity of ethylene glycol arises from its metabolites, particularly glycolic and oxalic acids. These compounds induce metabolic acidosis, lead to renal failure through calcium oxalate crystal deposition in the kidneys, and can cause neurological impairment. The anion gap increases due to the accumulation of these acids, leading to complications such as cardiovascular instability and potential multi-organ failure.

Pharmacokinetics

Ethylene glycol is rapidly absorbed after oral ingestion. It undergoes first-pass metabolism primarily in the liver, where it is converted into its toxic metabolites. The elimination half-life of ethylene glycol varies but is generally prolonged in cases of renal impairment. Renal excretion of metabolites contributes to the duration of toxicity, necessitating prompt medical intervention in cases of overdose.

Adverse effects

• Metabolic acidosis
• Renal failure
• CNS depression
• Hypocalcemia
• Cardiovascular collapse
• Pulmonary edema

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of metabolic acidosis
• Evaluate electrolyte levels, particularly calcium

Pregnancy

There is limited data on the safety of ethylene glycol in pregnancy. It should only be used if clearly needed.

Breast-feeding

It is unknown if ethylene glycol is excreted in human milk. Caution is advised.

Storage

Store in a tightly closed container at room temperature, away from heat and moisture.

Formulations

• Liquid

Dosage

Children: Refer to specific pediatric dosing guidelines based on the identified drug, as 'hard' does not provide sufficient information.

Adults: Refer to specific drug information for dosing guidelines, as 'hard' does not specify a particular medication.

Mechanism of action

The mechanism of action for drugs termed 'hard' must be specified for accurate information, as this phrase does not designate a specific compound. Mechanisms may involve receptor interaction, enzyme inhibition, or modulation of biochemical pathways, depending on the drug in question. For example, opioid analgesics work primarily by binding to mu-opioid receptors in the central nervous system, leading to analgesic effects.

Pharmacodynamics

Pharmacodynamics refers to the effects of a drug on the body and its mechanisms of action. The pharmacodynamics of any drug classified as 'hard' would depend on its specific pharmacological profile, including its efficacy, potency, and the nature of its therapeutic effects. For instance, in the case of opioids, pharmacodynamic effects include pain relief, sedation, and potential respiratory depression.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. The pharmacokinetics of a substance termed 'hard' would vary significantly based on the specific drug. For many medications, absorption may occur via oral or parenteral routes, distribution may involve binding to plasma proteins, metabolism may occur in the liver, and excretion is typically renal. Each of these parameters is critical for understanding the drug's action and potential side effects.

Pregnancy

Consult a healthcare professional before use, as safety has not been established.

Breast-feeding

Consult a healthcare professional before use, as safety has not been established.

Storage

Store in a cool, dry place, away from direct sunlight.

Dosage

Children: Paediatric dosing information is not standardized and should be derived from specific product guidelines or expert consultation.

Adults: Dosage and usage depend on the specific hydrogenated compound and its intended therapeutic application. Refer to specific product guidelines for detailed dosing information.

Mechanism of action

Hydrogenation alters the molecular structure of fatty acids, transforming double bonds into single bonds. This process increases the saturation level of fats, which can influence their metabolic pathways and lipid profiles in the body.

Pharmacodynamics

The pharmacodynamic effects of hydrogenated compounds depend on the specific substance being hydrogenated. Generally, hydrogenated fats can affect lipid metabolism, potentially leading to increased levels of LDL cholesterol and decreased levels of HDL cholesterol when consumed in excess. The physiological effects may include changes in insulin sensitivity and inflammatory responses.

Pharmacokinetics

The pharmacokinetics of hydrogenated compounds vary widely based on the specific hydrogenated product. Generally, these compounds are absorbed in the gastrointestinal tract, where they may undergo further metabolism by enzymes. The bioavailability, distribution, metabolism, and excretion depend on the fatty acid composition and the presence of other dietary components.

Pregnancy

Hydrogenated compounds, depending on their specific type, may have varying safety profiles in pregnancy. It is essential to consult specific guidelines or studies related to the particular hydrogenated substance in question.

Breast-feeding

The safety of hydrogenated compounds during breastfeeding may vary. Consultation with healthcare professionals regarding specific substances is advisable.

Storage

Hydrogenated substances should be stored in a cool, dry place, away from direct sunlight and heat to maintain stability.

Indications

• Anxiety disorders
• Nausea and vomiting
• Allergic conditions
• Preoperative sedation
• Pruritus

Dosage

Children: Refer to the BNF for Children for appropriate dosing recommendations based on age and weight.

Adults: Refer to the BNF for specific dosing guidelines based on the indication and patient characteristics.

Mechanism of action

Hydroxyzine works by antagonizing the H1 histamine receptors, leading to a reduction in the effects of histamine in the body. This action helps alleviate symptoms of allergic reactions and promotes sedation. Additionally, it may exert effects on serotonin and adrenergic receptors, which could contribute to its anxiolytic properties. Hydroxyzine is also involved in various metabolic pathways, including selenium metabolism and the degradation of reactive oxygen species.

Pharmacodynamics

The pharmacodynamic effects of hydroxyzine include sedation, anxiolysis, and reduction of allergic symptoms. Its sedative effects can make it useful in managing anxiety and inducing sleep, while its antihistaminic properties help to relieve symptoms such as itching and rashes associated with allergic reactions. The onset of action is typically within 15 to 30 minutes when taken orally, with peak effects occurring within 1 to 2 hours.

Pharmacokinetics

Hydroxyzine is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2 hours after oral administration. It is extensively metabolized in the liver, with metabolites, including cetirizine, possessing their own therapeutic effects. Hydroxyzine has a half-life of approximately 20 hours, allowing for once or twice daily dosing. It is primarily excreted in the urine, with less than 1% of the unchanged drug found in urine.

Interactions

• hydroxyzine+antiepileptics: Severe (increases risk of overheating and dehydration)
• hydroxyzine+zonisamide: Severe (increases risk of overheating and dehydration)
• hydroxychloroquine+penicillamine: Severe (increases risk of haematological toxicity)
• hydroxychloroquine+agalsidase alfa: Unknown (decreases effects)
• hydroxychloroquine+agalsidase beta: Unknown (decreases exposure)
• hydroxychloroquine+oral cholera vaccine: Unknown (decreases efficacy)
• live vaccines+hydroxy carbamide: Unknown (increases risk of generalised infection (possibly life-threatening))
• lanthanum+hydroxychloroquine: Unknown (decreases absorption)
• macrolides+hydroxychloroquine: Unknown (increases risk of serious cardiovascular adverse effects)
• hydroxychloroquine+remdesivir: Unknown (decreases effects)

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution. Hydroxychloroquine is excreted in breast milk, and effects on the infant are unknown.

Storage

Store in a cool, dry place, protected from light. Keep out of reach of children.

Formulations

• Tablets
• Oral solution

Indications

• Antiseptic for skin disinfection
• Solvent in pharmaceutical formulations
• Cleaning agent in laboratories and healthcare settings

Dosage

Children: For pediatric use, consult specific guidelines in the BNF for Children, as dosing may vary based on age, weight, and clinical circumstances.

Adults: For skin antisepsis, apply isopropyl alcohol topically in a concentration of 70% to the affected area. Dosage may vary based on clinical indication and setting.

Mechanism of action

Isopropyl alcohol works primarily as an antiseptic by denaturing proteins and disrupting cell membranes of bacteria, viruses, and fungi, leading to cell lysis and death. Its efficacy is enhanced by the presence of water, which facilitates the penetration of the alcohol into microbial cells.

Pharmacodynamics

Isopropyl alcohol exhibits a rapid onset of action against a variety of pathogens, including gram-positive and gram-negative bacteria, fungi, and some viruses. Its antimicrobial activity is concentration-dependent, with higher concentrations generally providing a broader spectrum of activity. It is commonly used in concentrations ranging from 60% to 90%, with 70% being optimal for disinfection due to its ability to penetrate the cell wall effectively.

Pharmacokinetics

Isopropyl alcohol is readily absorbed through the skin and mucous membranes. After absorption, it is metabolized primarily in the liver to acetone, which is then further metabolized and excreted, mostly via urine. The elimination half-life of isopropyl alcohol varies but is typically around 2 to 3 hours. Its effects can be influenced by factors such as dosage, route of exposure, and individual metabolic differences.

Pregnancy

Isopropyl alcohol should be used with caution during pregnancy. It is a category C drug, indicating that risk cannot be ruled out.

Breast-feeding

Caution is advised when using isopropyl alcohol during breastfeeding, as it is not known if it is excreted in human milk.

Storage

Isopropyl alcohol should be stored at room temperature, away from heat and flame. Keep the container tightly closed and in a well-ventilated area.

Formulations

• Isopropyl alcohol 70% solution
• Isopropyl alcohol 99% solution

Dosage

Children: Refer to specific product guidelines as dosage will depend on the type of medium and its intended application.

Adults: Refer to specific product guidelines as dosage will depend on the type of medium and its intended application.

Mechanism of action

The mechanism of action for a medium can vary greatly depending on the specific medium being referenced. Generally, media serve to maintain the stability and viability of cells or organisms during culture, enabling metabolic processes to occur. For instance, nutrient media provide essential nutrients, while selective media may inhibit the growth of certain organisms while promoting others.

Pharmacodynamics

Pharmacodynamics is largely dependent on the type of medium used and its components. In tissue cultures, the medium can influence cell growth, differentiation, and physiological responses. The interactions of cells with their environment are critical for cellular signaling and function.

Pharmacokinetics

Pharmacokinetics is not typically applicable to media in the same way it is for active drugs. However, the absorption and distribution of substances within a medium can affect how well the active ingredients are delivered or how organisms interact with the medium. Factors such as pH, osmolarity, and nutrient concentration can all influence these processes.

Pregnancy

Consult a healthcare provider before use, as the safety of medium in pregnancy has not been established.

Breast-feeding

Consult a healthcare provider before use, as it is unknown whether medium passes into breast milk.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Dosage

Children: Refer to product-specific guidelines or literature for dosing information, as methacrylic acid is primarily used in industrial and medical applications rather than as a direct therapeutic agent.

Adults: Refer to product-specific guidelines or literature for dosing information, as methacrylic acid is primarily used in industrial and medical applications rather than as a direct therapeutic agent.

Mechanism of action

Methacrylic acid functions primarily as a monomer that undergoes polymerization to form methacrylate-based polymers. The polymerization process can be initiated by thermal, chemical, or photoinitiated methods, resulting in the formation of cross-linked networks that provide structural integrity and durability to the final product. It interacts with radical initiators to form reactive free radicals that propagate the polymer chain growth.

Pharmacodynamics

Methacrylic acid and its derivatives exhibit good mechanical properties and biocompatibility, making them suitable for use in medical and dental applications. The polymers formed from methacrylic acid demonstrate resistance to wear, chemical degradation, and UV light, which enhances their stability and longevity in various environments. The biocompatibility of methacrylate polymers is essential for their application in medical devices, ensuring minimal adverse reactions upon implantation.

Pharmacokinetics

The pharmacokinetics of methacrylic acid is not extensively characterized due to its primary use as a polymer precursor rather than a therapeutic agent. However, when released in vivo, it is assumed to undergo rapid metabolism. The compound is likely to be absorbed through various routes, but specific absorption, distribution, metabolism, and excretion (ADME) data are limited. As a low molecular weight organic acid, it may be subject to conjugation and subsequent elimination through renal pathways.

Pregnancy

Methacrylic acid and its derivatives should be used with caution during pregnancy, as there is limited data on their safety. It is advisable to avoid use unless the potential benefits outweigh the risks.

Breast-feeding

There is insufficient information regarding the excretion of methacrylic acid into human milk. Caution is advised when administered to breastfeeding women.

Storage

Store in a cool, dry place away from direct sunlight. Keep containers tightly closed when not in use.

Indications

• Allergic conditions
• Autoimmune diseases
• Asthma and chronic obstructive pulmonary disease (COPD)
• Certain cancers (e.g., leukemia, lymphoma)
• Skin conditions (e.g., dermatitis)
• Inflammatory bowel disease
• Multiple sclerosis exacerbations
• Severe infections requiring immunosuppression

Dosage

Children: Refer to BNF for Children for specific dosing; doses vary significantly based on the child's age, weight, and condition being treated.

Adults: Refer to BNF for specific dosing; typically, initial doses range from 4 to 48 mg depending on the severity of the condition.

Mechanism of action

Methylprednisolone exerts its effects by binding to glucocorticoid receptors, leading to the modulation of gene expression. This interaction influences the transcription of anti-inflammatory proteins while suppressing the expression of pro-inflammatory genes, ultimately resulting in reduced inflammation and immune response.

Pharmacodynamics

The pharmacodynamic effects of methylprednisolone are characterized by its ability to decrease inflammation, suppress the immune response, and affect carbohydrate metabolism. Therapeutic doses lead to various systemic effects, including modification of leukocyte distribution and inhibition of cytokine production.

Pharmacokinetics

Methylprednisolone is well absorbed after oral administration, with a bioavailability of approximately 50%. It has a volume of distribution that reflects extensive tissue binding. The drug is metabolized primarily in the liver through conjugation and reduction, and its metabolites are excreted in urine. The half-life varies based on the route of administration but is generally around 18 to 36 hours.

Adverse effects

• Increased blood pressure
• Hyperglycemia
• Weight gain
• Mood changes
• Insomnia
• Gastrointestinal disturbances
• Increased susceptibility to infections

Interactions

• methylphenidate+apraclonidine: Severe (decreases effects)
• methylthioninium chloride+bupropion: Severe (increases risk of severe hypertension)
• methylphenidate+linezolid: Severe (increases risk of elevated blood pressure)
• rasagiline+methylphenidate: Severe (increases risk of a hypertensive crisis)
• mao-inhibitors+methylphenidate: Severe (increases risk of a hypertensive crisis)
• dronedarone+methylprednisolone: Moderate (increases exposure)
• miconazole+methylprednisolone: Moderate (increases concentration)
• antifungals, azoles+methylprednisolone: Moderate (increases exposure)
• crizotinib+methylprednisolone: Moderate (increases exposure)

Precautions

• Use with caution in patients with hypertension
• Monitor blood glucose levels in diabetic patients
• Consider potential for infection risk due to immunosuppression
• Evaluate for psychiatric effects in susceptible individuals

Pregnancy

Corticosteroids may be used during pregnancy if the potential benefit justifies the risk to the fetus. Careful monitoring is advised.

Breast-feeding

Corticosteroids are excreted in breast milk; caution is advised. Monitor the infant for potential effects.

Storage

Store in a cool, dry place, away from light. Keep out of reach of children.

Formulations

• Tablets
• Injectable solutions
• Topical preparations

Mechanism of action

Methylsulphate functions as a methylating agent, transferring a methyl group to nucleophiles. This process involves the formation of a sulfonium ion, which is highly reactive and can readily react with nucleophilic sites on various substrates, leading to methylation reactions.

Pharmacodynamics

The pharmacodynamics of methylsulphate is primarily related to its role as a methylating agent in biochemical reactions. It can alter the structure and function of biological molecules, potentially affecting cellular processes and signaling pathways. However, detailed pharmacodynamic studies specific to therapeutic use are limited.

Pharmacokinetics

There is limited information on the pharmacokinetics of methylsulphate, given its typical use as a reagent in laboratory settings rather than a clinical drug. When used in chemical reactions, its reactivity and transformation into other compounds would dictate its pharmacokinetic profile, which could vary significantly based on the specific context of use.

Pregnancy

There is limited data on the use of methylsulphate in pregnancy. Consult relevant guidelines.

Breast-feeding

Data on the excretion of methylsulphate in human milk is not available. Caution is advised.

Storage

Store in a cool, dry place, away from direct sunlight.

Indications

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

Store in a cool, dry place away from direct sunlight and moisture.

Dosage

Children: Refer to specific product information for pediatric dosing, which is determined by the active ingredient and concentration.

Adults: Refer to specific product information for dosing as it varies with the active ingredient and concentration.

Mechanism of action

The mechanism of action for a drug referred to as 'percent' would depend on the specific active ingredient present in the formulation. For instance, in a solution of a certain concentration, the pharmacological effects would be derived from the active component's interaction with biological receptors or pathways, leading to a therapeutic effect.

Pharmacodynamics

Pharmacodynamics will vary based on the active ingredient represented by the 'percent'. Generally, it involves the interaction of the drug with its receptor, the resulting biological response, and the relationship between drug concentration and effect. This can include agonistic or antagonistic effects on receptors, modulation of enzyme activity, or alteration of cellular signaling pathways.

Pharmacokinetics

Pharmacokinetics details how a drug is absorbed, distributed, metabolized, and excreted from the body. The specific pharmacokinetic profile would depend on the formulation and active ingredient, including absorption rates, bioavailability, volume of distribution, metabolism (often via the liver), and excretion (primarily through urine or bile).

Pregnancy

Consult a healthcare provider for individual assessment, as effects may vary depending on the specific use and formulation.

Breast-feeding

Consult a healthcare provider for individual assessment, as effects may vary depending on the specific use and formulation.

Storage

Store in a cool, dry place away from direct sunlight and moisture.

Indications

• Constipation
• Bowel preparation prior to surgical procedures or diagnostic tests

Dosage

Children: Refer to specific guidelines or BNF for Children for dosing information.

Adults: Refer to specific guidelines or BNF for detailed dosing information.

Mechanism of action

Polyethylene glycol works by osmotically retaining water in the intestinal lumen, which increases the water content of the stool. This enhances the passage of stool through the intestines and promotes bowel movements. The high molecular weight of polyethylene glycol prevents its absorption in the gastrointestinal tract, ensuring that it remains in the lumen to exert its effects.

Pharmacodynamics

The pharmacodynamic profile of polyethylene glycol involves its ability to increase stool water content, thereby reducing stool consistency and facilitating easier passage. It does not stimulate intestinal motility directly but rather relies on the osmotic effect to promote bowel evacuation. The onset of action typically occurs within 24 to 96 hours after ingestion.

Pharmacokinetics

Polyethylene glycol is not absorbed systemically, and its pharmacokinetics are characterized by its presence solely in the gastrointestinal tract. It is excreted unchanged in the stool. The volume of polyethylene glycol administered can influence the effectiveness and timing of its action, but its absorption is negligible, making systemic side effects rare.

Adverse effects

• Abdominal cramping
• Diarrhea
• Nausea
• Vomiting
• Bloating
• Flatulence

Precautions

• Use with caution in patients with gastrointestinal disorders or bowel obstruction.
• Ensure adequate hydration during use to prevent dehydration.

Pregnancy

Polyethylene glycol is generally considered safe during pregnancy, but should be used under medical supervision.

Breast-feeding

Polyethylene glycol is excreted in breast milk in very small amounts and is generally regarded as safe during breastfeeding.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Powder for oral solution
• Liquid formulation

Indications

• Constipation
• Bowel preparation before colonoscopy or surgery

Dosage

Children: Refer to specific product guidelines for dosing instructions.

Adults: Refer to specific product guidelines for dosing instructions.

Mechanism of action

Polyoxyl works by retaining water in the stool, increasing its bulk and consistency. This osmotic effect stimulates bowel movements by softening the stool and promoting peristalsis. The water-retaining properties are attributed to its high molecular weight and hydrophilicity, which allow it to attract and hold water within the gastrointestinal tract.

Pharmacodynamics

The pharmacodynamic profile of polyoxyl includes its ability to enhance stool water content, thereby improving fecal passage through the intestines. This results in increased stool frequency and decreased transit time. Polyoxyl does not significantly affect electrolyte balance, making it a safe option for chronic constipation management.

Pharmacokinetics

Polyoxyl is not absorbed systemically; it remains in the gastrointestinal tract where it exerts its effects. The onset of action can vary but typically occurs within 24 to 72 hours after administration. The elimination of polyoxyl occurs through fecal excretion, with no significant metabolism or renal clearance involved.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal cramps
• Allergic reactions

Precautions

• Use with caution in patients with gastrointestinal disorders.
• Monitor for allergic reactions in patients with a history of hypersensitivity.

Pregnancy

Polyoxyl is generally regarded as safe for use during pregnancy, but specific clinical guidance should be consulted.

Breast-feeding

Polyoxyl is considered safe during breastfeeding, though maternal factors should be assessed.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Oral solution
• Tablet
• Topical cream

Indications

• Emulsifying agent in drug formulations
• Stabilizer for parenteral preparations
• Solubilizer for hydrophobic drug compounds
• Ingredient in topical formulations

Dosage

Children: Refer to specific product guidelines, as dosing varies based on formulation and intended use.

Adults: Refer to specific product guidelines, as dosing varies based on formulation and intended use.

Mechanism of action

Polysorbate functions primarily as an emulsifying agent. It reduces the surface tension between immiscible liquids, allowing them to mix more easily. This property is particularly useful in stabilizing emulsions and suspensions, facilitating the delivery of active pharmaceutical ingredients in various formulations.

Pharmacodynamics

Polysorbate does not exert pharmacological effects in the traditional sense, as it does not bind to specific receptors to elicit a physiological response. Instead, it plays a crucial role in modifying the physical properties of drug formulations, thereby enhancing drug delivery and absorption. Its ability to solubilize drugs enhances their bioavailability, particularly for poorly soluble compounds.

Pharmacokinetics

Polysorbate is generally considered to be non-toxic and is not absorbed to a significant extent when administered orally. It is metabolized by the liver and excreted primarily through the gastrointestinal tract. The pharmacokinetic profile may vary depending on the route of administration and the specific formulation in which it is used.

Adverse effects

• Allergic reactions
• Skin irritation
• Gastrointestinal disturbances

Precautions

• Use cautiously in patients with known allergies to polysorbates or related compounds
• Monitor for allergic reactions in susceptible individuals

Pregnancy

Polysorbate is generally considered safe for use during pregnancy, but consult with a healthcare provider for specific cases.

Breast-feeding

Polysorbate is considered safe during breastfeeding, but consult with a healthcare provider for individual advice.

Storage

Store at room temperature, away from direct sunlight and moisture.

Formulations

• Polysorbate 20
• Polysorbate 80

Indications

• Topical antiseptic for skin disinfection
• Surgical scrubs and hand sanitizers
• Wound care management
• Pharmaceutical excipient in solid and liquid formulations

Dosage

Children: Refer to specific product guidelines for pediatric dosing recommendations, as doses can vary based on formulation and intended use.

Adults: Refer to specific product guidelines for dosing recommendations, as doses can vary based on the formulation and intended use.

Mechanism of action

Povidone acts by forming a complex with iodine when used as an antiseptic, which releases iodine slowly to exert its antimicrobial effect. The iodine disrupts microbial cell walls and interferes with protein synthesis, leading to cell death. Additionally, as a polymer, povidone can enhance drug solubility and stability by forming a hydrophilic matrix.

Pharmacodynamics

Povidone has a broad spectrum of antimicrobial activity against bacteria, viruses, and fungi. Its antiseptic properties are primarily due to the release of iodine, which is effective in reducing microbial load and preventing infection. The polymer's ability to bind to various substances allows it to be utilized in formulations that require improved stability and solubility.

Pharmacokinetics

Povidone is not absorbed systemically when applied topically, as it remains localized at the site of application. Its pharmacokinetics are largely dependent on the formulation and route of administration, with the polymer being metabolized by hydrolysis and excreted in urine as low-molecular-weight compounds. The release and activity of iodine are influenced by the concentration of povidone and the presence of organic matter.

Adverse effects

• Local irritation
• Allergic reactions
• Skin rashes
• Hypersensitivity reactions

Precautions

• Use with caution in patients with known allergies to iodine or povidone-iodine
• Avoid use in deep puncture wounds or serious burns

Pregnancy

Povidone is generally considered safe for use during pregnancy, but it is advisable to consult a healthcare professional before use.

Breast-feeding

Povidone is considered safe during breastfeeding, but it is recommended to consult a healthcare professional.

Storage

Store at room temperature, away from moisture and heat. Keep the container tightly closed.

Formulations

• Topical solution
• Ointment
• Surgical scrub
• Gauze impregnated with povidone-iodine

Indications

• Hyperthyroidism
• Graves' disease
• Thyroid storm

Dosage

Children: Refer to the BNF

Adults: The usual initial dose of propylthiouracil in adults is 300 mg per day, divided into 3 doses. The maintenance dose is typically 100-150 mg per day, adjusted based on thyroid function tests.

Mechanism of action

Propylthiouracil acts by inhibiting the enzyme thyroid peroxidase, which is involved in the iodination of tyrosine residues in thyroglobulin, a precursor of thyroid hormones. By blocking this enzyme, PTU reduces the production of thyroxine (T4) and triiodothyronine (T3), leading to decreased thyroid hormone levels in circulation. Additionally, PTU inhibits the conversion of T4 to T3 in peripheral tissues, further contributing to its antithyroid effects.

Pharmacodynamics

The pharmacodynamic effects of propylthiouracil are primarily centered around its ability to lower thyroid hormone levels, which helps alleviate symptoms of hyperthyroidism such as increased heart rate, weight loss, and anxiety. The onset of action can vary, but therapeutic effects may be observed within several weeks of initiation. Monitoring thyroid function tests is essential to assess the efficacy and adjust dosing as needed.

Pharmacokinetics

Propylthiouracil is well absorbed from the gastrointestinal tract, though its bioavailability can be affected by factors such as food intake. The drug is extensively metabolized in the liver, and its elimination half-life averages around 1-2 hours. Most of the drug is excreted in urine as metabolites. It is important to note that due to its rapid metabolism, multiple daily doses may be required to maintain therapeutic levels.

Interactions

• propylthiouracil+metyrapone: Severe (decreases effects)

Dosage

Children: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Adults: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Mechanism of action

The mechanism of action for purified compounds varies widely depending on the specific substance. Generally, purified drugs exert their effects by interacting with specific biological targets, such as receptors, enzymes, or ion channels, leading to a desired therapeutic effect. This interaction can involve binding to receptors to activate or inhibit signaling pathways, modulating enzymatic activity, or altering physiological processes.

Pharmacodynamics

Pharmacodynamics describes the effects of a drug on the body and the relationship between drug concentration and effect. For purified drugs, this can involve dose-response relationships and the time course of their action. The purified form often enhances potency and reduces variability in response among patients, which can lead to more predictable therapeutic outcomes. The overall effect is determined by the drug's affinity for its target, the efficacy of the drug-receptor interaction, and the downstream signaling pathways activated as a result of this interaction.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. For purified substances, absorption can be more efficient due to the absence of impurities that may affect solubility or stability. Distribution may also be enhanced, leading to higher bioavailability. Metabolism can be influenced by the structure of the purified compound, as it may be metabolized more readily by liver enzymes. Excretion typically occurs through the kidneys or liver, depending on the molecular characteristics of the purified drug.

Pregnancy

Consult with a healthcare professional, as the safety of purified forms of medications during pregnancy may vary depending on the specific substance.

Breast-feeding

Consult with a healthcare professional, as the safety of purified forms of medications during breastfeeding may vary depending on the specific substance.

Storage

Store in a cool, dry place, away from light and moisture, and keep out of reach of children.

Indications

• Potential role in bone health
• Support for connective tissue formation
• May aid in mineral metabolism

Dosage

Children: There is no established clinical dosage for silicon in paediatric populations, as it is not classified as an essential nutrient.

Adults: There is no established clinical dosage for silicon in adults, as it is not classified as an essential nutrient.

Mechanism of action

Silicon is believed to enhance the synthesis of glycosaminoglycans and collagen, which are important for the structural integrity of connective tissues. It may also influence the activity of certain enzymes involved in bone mineralization, thus playing a role in maintaining bone density and health.

Pharmacodynamics

The pharmacodynamics of silicon is not fully elucidated; however, it is thought to involve the modulation of bone metabolism and the promotion of connective tissue health. Silicon may have a synergistic effect with other minerals, such as calcium and magnesium, aiding in their utilization and metabolism in the body.

Pharmacokinetics

The pharmacokinetics of silicon is complex, as it is not absorbed through typical gastrointestinal pathways. Instead, silicon is thought to be taken up in the form of silicates and then distributed throughout the body, particularly in connective tissues. The elimination of silicon occurs primarily through renal excretion, with some variations depending on dietary intake and individual metabolism.

Pregnancy

Silicon is generally considered safe during pregnancy, as it is a naturally occurring element in the human body. However, specific recommendations regarding supplementation should be followed based on the advice of a healthcare provider.

Breast-feeding

Silicon is present in breast milk in small amounts. Its safety during breastfeeding is generally regarded as acceptable, although supplementation should be approached with caution and under medical advice.

Storage

Silicon should be stored in a cool, dry place, protected from light and moisture. Follow specific storage recommendations provided by the manufacturer if available.

Dosage

Children: Refer to the specific drug's prescribing information for paediatric dosing guidelines.

Adults: Refer to the specific drug's prescribing information for adult dosing guidelines.

Mechanism of action

The mechanism of action would depend on the specific drug referred to by 'size'. Generally, drugs exert their effects through interaction with biological targets such as receptors, enzymes, or ion channels, leading to a physiological response.

Pharmacodynamics

Pharmacodynamics refers to the effects of the drug on the body, including the relationship between drug concentration and effect. This can involve receptor binding, signal transduction, and the resulting biological effects. Specific dynamics would vary based on the drug in question.

Pharmacokinetics

Pharmacokinetics describes the absorption, distribution, metabolism, and excretion (ADME) of a drug. Factors such as bioavailability, volume of distribution, half-life, and clearance would vary significantly based on the specific drug being considered.

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Use with caution, as it is not known whether it is excreted in human milk.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Used as an excipient in drug formulations
• Pleurodesis for the management of recurrent pleural effusions

Dosage

Children: Refer to specific guidelines for paediatric use, as dosing may differ based on age and clinical condition.

Adults: Refer to specific guidelines for the appropriate dosage in pleurodesis and other applications, as it may vary based on clinical context.

Mechanism of action

Talc exhibits very good absorptive properties, allowing it to absorb moisture and other substances effectively. This characteristic is particularly useful in pharmaceutical formulations, where it may enhance the stability and texture of the drug product.

Pharmacodynamics

Talc's primary pharmacodynamic effect is its ability to act as an inert filler and bulking agent in pharmaceutical preparations. It does not have any intrinsic pharmacological activity but serves to improve the physical properties of formulations, such as flowability and compressibility.

Pharmacokinetics

Talc is not absorbed systemically when used as an excipient or in medical procedures. Its effects are local, and it remains in the site of application, where it functions primarily as a mechanical agent. The pharmacokinetics of talc in the context of its use in pleurodesis involves its ability to promote adhesion of the pleural surfaces, thereby preventing fluid accumulation.

Pregnancy

Talc is classified as a substance with minimal systemic absorption, but safety during pregnancy has not been well established. Consult relevant guidelines.

Breast-feeding

Talc is not expected to be absorbed in significant amounts; however, caution is advised and consult guidelines.

Storage

Store in a cool, dry place, away from direct sunlight.

Indications

• Benign Prostatic Hyperplasia (BPH)
• Lower urinary tract symptoms associated with BPH

Dosage

Children: null

Adults: The usual dose is 400 micrograms once daily, taken approximately 30 minutes after the same meal each day.

Mechanism of action

Tamsulosin selectively blocks alpha-1A and alpha-1D adrenoceptors, which are prevalent in the prostate and bladder respectively. This leads to relaxation of the smooth muscle in the prostate and the bladder neck, thereby enhancing urinary flow. The drug's specific action on alpha-1A receptors minimizes effects on vascular smooth muscle, resulting in a lower incidence of adverse cardiovascular effects.

Pharmacodynamics

Tamsulosin exhibits selective antagonism of alpha-1 adrenergic receptors, with a greater affinity for alpha-1A and alpha-1D subtypes compared to alpha-1B. This selectivity allows for effective relief of urinary symptoms associated with BPH while reducing the risk of orthostatic hypotension and other cardiovascular side effects. Its pharmacodynamic profile supports improved urinary flow rates without significant hemodynamic changes.

Pharmacokinetics

Tamsulosin is well absorbed after oral administration and reaches peak plasma concentrations within 4 to 6 hours. It has a high protein binding rate (approximately 99%) and is primarily metabolized by the liver via cytochrome P450 enzymes, notably CYP3A4. The elimination half-life is approximately 9 to 15 hours, allowing for once-daily dosing. The drug is excreted mainly in the urine, with both unchanged drug and metabolites found in the urine.

Adverse effects

• dizziness
• headache
• nasal congestion
• semen abnormality
• orthostatic hypotension

Interactions

• cobicistat+tamsulosin: Moderate (increases exposure)
• idelalisib+tamsulosin: Moderate (increases exposure)
• antifungals, azoles+tamsulosin: Unknown (increases exposure)
• crizotinib+tamsulosin: Unknown (increases exposure)
• imatinib+tamsulosin: Unknown (increases exposure)
• letermovir+tamsulosin: Unknown (increases exposure)
• nilotinib+tamsulosin: Unknown (increases exposure)
• dronedarone+tamsulosin: Unknown (increases exposure)
• erythromycin+tamsulosin: Unknown (increases exposure)

Pregnancy

Tamsulosin is not recommended during pregnancy due to limited data on its safety.

Breast-feeding

It is unknown whether tamsulosin is excreted in human milk; caution is advised.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Capsules 0.4 mg

Indications

• Orthopedic implants
• Dental implants
• Prosthetic devices
• Surgical instruments

Mechanism of action

Titanium does not have a specific mechanism of action as it is not a drug in the traditional sense. Instead, its biocompatibility allows it to integrate with biological tissues without eliciting significant immune responses, making it suitable for use in implants and prosthetic devices. The presence of titanium ions can influence biological processes, including cell proliferation and differentiation.

Pharmacodynamics

Titanium itself does not exhibit pharmacodynamics as it is not administered as a drug. Its interactions within biological systems are primarily mechanical and structural, providing support and stability in orthopedic and dental applications. The biocompatibility of titanium allows for favorable tissue integration and reduced rejection rates compared to other materials.

Pharmacokinetics

As titanium is not a pharmacological agent, traditional pharmacokinetic parameters such as absorption, distribution, metabolism, and excretion do not apply. Titanium is typically utilized in solid forms, such as implants, where it remains localized and does not undergo metabolism or systemic circulation.

Pregnancy

There is limited data on the use of titanium during pregnancy. Consult a healthcare professional before use.

Breast-feeding

There is limited data on the excretion of titanium in breast milk. Consult a healthcare professional before use.

Storage

Store in a cool, dry place away from direct sunlight.

Dosage

Children: Refer to established guidelines for exposure and toxicity management as there is no standard dosing for therapeutic use.

Adults: Refer to established guidelines for exposure and toxicity management as there is no standard dosing for therapeutic use.

Mechanism of action

Toluene exerts its effects primarily through the central nervous system. It acts as a non-specific CNS depressant, interfering with neurotransmitter systems and causing disruption in synaptic transmission. Toluene is known to enhance the inhibitory effects of GABA (gamma-aminobutyric acid) and may inhibit NMDA (N-methyl-D-aspartate) receptors, contributing to its sedative effects.

Pharmacodynamics

The pharmacodynamic effects of toluene include sedation, euphoria, and decreased cognitive and motor functions. Due to its lipophilic nature, toluene readily crosses the blood-brain barrier, leading to central nervous system effects. Toxicological effects can include headaches, dizziness, ataxia, and, in severe cases, unconsciousness or coma. Chronic exposure can lead to neurotoxicity and cognitive deficits.

Pharmacokinetics

Toluene is rapidly absorbed through inhalation, as well as through the gastrointestinal tract and skin. It is widely distributed in body tissues, particularly in lipid-rich organs like the brain and adipose tissue. Metabolism occurs primarily in the liver via cytochrome P450 enzymes, leading to the formation of various metabolites, including benzyl alcohol and benzoic acid. Excretion occurs mainly through urine, with a half-life that can vary depending on the route of exposure and individual factors.

Adverse effects

• Headache
• Dizziness
• Nausea
• Vomiting
• Central nervous system depression
• Respiratory irritation
• Dermatitis
• Liver damage
• Kidney damage
• Hearing loss

Precautions

• Use with caution in patients with a history of substance abuse
• Avoid exposure in patients with respiratory diseases
• Handle with care in pregnant women due to potential teratogenic effects
• Ensure adequate ventilation when using toluene

Pregnancy

Toluene is classified as a teratogen and can cause developmental issues in the fetus if exposure occurs during pregnancy. Caution is advised.

Breast-feeding

Toluene can be excreted in breast milk. Caution is advised for nursing mothers to avoid exposure.

Storage

Store in a cool, dry place away from direct sunlight and heat sources. Keep container tightly closed.

Formulations

• Solvent
• Aerosol spray
• Adhesives
• Paint thinners

Dosage

Children: Refer to specific guidelines or pharmacological texts, as no established clinical dosing is available.

Adults: Refer to specific guidelines or pharmacological texts, as no established clinical dosing is available.

Mechanism of action

Triethyl functions as an alkylating agent, introducing alkyl groups into various substrates, which can lead to the modification of nucleic acids and proteins. This mechanism can result in the disruption of normal cellular processes, including inhibition of DNA replication and transcription, ultimately leading to cell death in susceptible cells. Its reactivity is primarily due to the presence of multiple ethyl groups, which can interact with nucleophilic sites in biological molecules.

Pharmacodynamics

The pharmacodynamics of triethyl are characterized by its ability to form covalent bonds with nucleophilic sites in biomolecules, influencing cellular functions and integrity. The modulation of DNA and protein function can lead to cytotoxic effects, particularly in rapidly dividing cells. Its effects may be dose-dependent, with higher concentrations resulting in increased toxicity and potential side effects.

Pharmacokinetics

Triethyl's pharmacokinetics are not well-studied in a clinical context, as it is primarily utilized in chemical processing rather than therapeutic applications. However, when considering alkylating agents in general, they may exhibit variable absorption, distribution, metabolism, and excretion depending on their chemical structure and the route of exposure. Following administration, such compounds can accumulate in tissues, particularly in the liver and kidneys, and may undergo metabolic transformation before excretion. Due to its reactive nature, triethyl can also pose risks of toxicity and adverse effects.

Adverse effects

• Nausea
• Vomiting
• Dizziness
• Headache
• Respiratory depression

Precautions

• Use with caution in patients with a history of respiratory issues
• Monitor liver function tests due to potential hepatotoxicity

Pregnancy

Triethyl is not recommended during pregnancy due to potential risks to the fetus.

Breast-feeding

Caution is advised as it is not known if triethyl is excreted in breast milk.

Storage

Store in a cool, dry place away from light and moisture.

Indications

• Hypertriglyceridemia
• Cardiovascular disease risk management
• Metabolic syndrome

Dosage

Children: In paediatric patients, management of elevated triglycerides should involve a thorough evaluation by a healthcare provider. Specific dosing will depend on the chosen pharmacotherapy and should be referred to established guidelines.

Adults: For adults, management of high triglycerides typically begins with lifestyle changes. If medication is indicated, the specific dosing regimen will depend on the drug selected and should be guided by clinical guidelines.

Mechanism of action

Triglycerides are primarily absorbed from dietary sources and synthesized in the liver. Their levels are regulated by hormones such as insulin and involve the action of lipoprotein lipase, which hydrolyzes triglycerides into free fatty acids for energy use. In pharmacological terms, certain medications such as fibrates and omega-3 fatty acids work by enhancing the clearance of triglycerides from the bloodstream.

Pharmacodynamics

Triglyceride levels are influenced by various factors including diet, physical activity, and hormonal regulation. High levels of triglycerides can lead to atherosclerosis, where plaque builds up in the arteries, potentially resulting in heart disease. Drugs that are used to lower triglyceride levels typically work by either reducing the synthesis of triglycerides in the liver or enhancing their breakdown and clearance.

Pharmacokinetics

Triglycerides are transported in the bloodstream as part of lipoproteins, mainly chylomicrons and very-low-density lipoproteins (VLDL). They are metabolized in peripheral tissues by lipoprotein lipase. The half-life of triglycerides in circulation is variable and depends on several factors including the type of lipoprotein and the individual’s metabolic state. The clearance and metabolism of triglycerides can also be affected by medications, lifestyle factors, and underlying health conditions.

Adverse effects

• Pancreatitis
• Abdominal pain
• Nausea
• Vomiting
• Fatigue
• Eruptive xanthomas
• Liver dysfunction

Precautions

• Use with caution in patients with a history of pancreatitis.
• Monitor liver function tests in patients receiving treatment that can affect triglyceride levels.
• Consider lifestyle modifications prior to pharmacological intervention.

Pregnancy

Elevated triglyceride levels can be common during pregnancy; however, significant increases should be monitored as they may pose risks for gestational diabetes and pancreatitis.

Breast-feeding

Some studies suggest that triglyceride levels may increase during lactation; however, clinical significance is typically low. Monitoring is advised.

Storage

Store in a cool, dry place away from light. Ensure that any medications related to triglycerides are stored according to the manufacturer's instructions.

Mechanism of action

Ethanol affects the brain’s neurons in several ways. It alters their membranes as well as their ion channels, enzymes, and receptors. Alcohol also binds directly to the receptors for acetylcholine, serotonin, GABA, and the NMDA receptors for glutamate. The sedative effects of ethanol are mediated through binding to GABA receptors and glycine receptors (alpha 1 and alpha 2 subunits). It also inhibits NMDA receptor functioning. In its role as an anti-infective, ethanol acts as an osmolyte or dehydrating agent that disrupts the osmotic balance across cell membranes. ... Ethanol is known to affect a large number of membrane proteins that participate in signaling pathways such as neurotransmitter receptors, enzymes, and ion channels, and there is extensive evidence that ethanol interacts with a variety of neurotransmitters. The major actions of ethanol involve enhancing the inhibitory effects of gamma-aminobutyric acid (GABA) at GABAa receptors and blockade of the N-methyl-D-aspartate (NMDA) subtype of glutamate, an excitatory amine acid (EAA) receptor. Animal studies indicate that the acute effects of ethanol result from competitive inhibition of glycine binding to NMDA receptor and disruption of glutamatergic neurotransmission by inhibiting the response of the NMDA receptor. Persistent glycine antagonism and attenuation of glutamatergic neurotransmission by chronic ethanol exposure results in tolerance to ethanol by enhancing EAA neurotransmission and NMDA receptor upregulation. The latter appears to involve selective increases in NMDA R2B subunit concentrations and other molecular changes in specific brain loci. The abrupt withdrawal of ethanol thus produces a hyperexcitable state that leads to the ethanol withdrawal syndrome and excitotoxic neuronal death. GABA-mediated inhibition, which normally acts to limit excitation, is eliminated during ethanol withdrawal syndrome and further intensifies this excitation. In addition, NMDA receptors function to inhibit the release of dopamine in the nucleus accumbens and mesolimbic structures, which modulate the reinforcing action of addictive xenobiotics such as ethanol. By inhibiting NMDA receptor activity, ethanol could increase dopamine release from the nucleus accumbens and ventral tegmental area and could thus create dependence. Chronic ethanol administration also results in tolerance, dependence, and an ethanol withdrawal syndrome, mediated, in part, by desensitization and or downregulation of GABAa receptors. The development of alcoholic ketoacidosis (AKA) requires that a combination of physical and physiologic events occur. The normal response to starvation and depletion of hepatic glycogen stores is for amino acids to be converted to pyruvate. Pyruvate can serve as a substrate for gluconeogenesis, be converted to acetyl-CoA, which can enter the Krebs cycle or can be utilized in various biosynthetic pathways (eg, fatty acid, ketone bodies, cholesterol, and acetylcholine) ... Ethanol metabolism generates NADH, resulting in an excess of reducing potential. This high redox state favors the conversion of pyruvate to lactate, diverting pyruvate from being a substrate for gluconeogenesis. To compensate for the lack of normal metabolic substrates, the body mobilizes fat from adipose tissue and increased fatty acid metabolism as an alternative source of energy. This response is mediated by a decrease in insulin and an increased secretion of glucagon, catecholamines, growth hormone, and cortisol. Fatty acid metabolism results in the formation of acetyl-CoA and it combines with the excess acetate that is generated from ethanol metabolism to form acetoacetate. Most of the acetoacetate is reduced to beta-hydroxybutyrate due to the excess reducing potential or high redox state of the cell. Volume depletion interferes with the renal elimination of acetoacetate and beta-hydroxybutyrate, and contributes to the acidosis. An elevated lactate concentration may result from shunting from pyruvate or

Pharmacodynamics

Alcohol produces injury to cells by dehydration and precipitation of the cytoplasm or protoplasm. This accounts for its bacteriocidal and antifungal action. When alcohol is injected in close proximity to nerve tissues, it produces neuritis and nerve degeneration (neurolysis). Ninety to 98% of ethanol that enters the body is completely oxidized. Ethanol is also used as a cosolvent to dissolve many insoluble drugs and to serve as a mild sedative in some medicinal formulations. Ethanol also binds to GABA, glycine, NMDA receptors and modulates their effects. Ethanol is also metabolised by the hepatic enzyme alcohol dehydrogenase.

Mechanism of action

The 5α-reductase is a nuclear-bound steroid intracellular enzyme primarily located in the prostatic stromal cell that converts the androgen testosterone into the more active metabolite, 5α-dihydrotestosterone (DHT). DHT is considered to be the primary androgen playing a role in the initial development and subsequent enlargement of the prostate gland. It serves as the hormonal mediator for the hyperplasia upon accumulation within the prostate gland. DHT displays a higher affinity towards androgen receptors in the prostate gland compared to testosterone and by acting on the androgen receptors, DHT modulates genes that are responsible for cell proliferation. Responsible for the synthesis of approximately one-third of circulating DHT, type I 5α-reductase is predominant in the sebaceous glands of most regions of skin, including the scalp, and liver. The type II 5a-reductase isozyme is primarily found in the prostate, seminal vesicles, epididymides, and hair follicles as well as liver, and is responsible for two-thirds of circulating DHT. Due to its dual inhibition of both isoenzymes of 5α-reductase, dutasteride causes a near-complete suppression of DHT. Compared to a 70% reduction of serum DHT levels caused by [finasteride], a near-complete suppression of serum DHT-more than 90% is seen with dutasteride. By forming a stable complex with both type I and type II 5α-reductase, dutasteride inhibits its enzymatic action of converting testosterone to 5α-dihydrotestosterone (DHT), which is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. It is proposed that DHT is the principal androgen responsible for prostatic growth in later life-normal masculinization of the external genitalia and maturation of the prostate gland during development-thus reducing the serum DHT levels results in reduced prostatic volume and increased epithelial apoptosis. Dutasteride is a competitive and specific inhibitor of both Type I and Type II 5α-reductase isoenzymes and when evaluated under _in vitro_ and _in vivo_ conditions, the dissociation of the drug from the drug-enzyme complex is reported to be extremely slow. Dutasteride does not bind to the human androgen receptor.

Pharmacodynamics

Dutasteride is a synthetic 4-azasteroid compound that selectively inhibits both the type I and type II isoforms of steroid 5α-reductase, an intracellular enzyme that converts testosterone to 5α-dihydrotestosterone (DHT). Dutasteride works by reducing the levels of circulating DHT. It was also shown to reduce the size of the prostate gland, improve urinary flow, and symptoms of benign prostatic hyperplasia alone or in combination with tamsulosin. The effect of the reduction of DHT by dutasteride is dose-dependent, with the maximum effect observed within 1-2 weeks following initial administration. After 1 and 2 weeks of daily dosing with dutasteride 0.5 mg, median serum DHT concentrations were reduced by 85% and 90%, respectively. The serum concentrations of DHT were maintained to be decreased by more than 90% in 85% of patients following 1 years' administration of oral dutasteride 0.5 mg/day. As evident from the clinical studies, dutasteride may also cause decreases in serum PSA in the presence of prostate cancer.

Mechanism of action

Paritaprevir is a potent inhibitor of the NS3/4A serine protease of Hepatitis C Virus (HCV). Following viral replication of HCV genetic material and translation into a single polypeptide, Nonstructural Protein 3 (NS3) and its activating cofactor Nonstructural Protein 4A (NS4A) are responsible for cleaving it into the following structural and nonstructural proteins required for assembly into mature virus: NS3, NS4A, NS4B, NS5A, and NS5B. By inhibiting viral protease NS3/4A, paritaprevir therefore prevents viral replication and function.

Pharmacodynamics

At concentrations approximately 6 and 1.8 times the therapeutic concentrations of paritaprevir and ombitasvir, the combination did not prolong QTc to any clinically relevant extent.

Mechanism of action

Ethylene glycol is metabolized by alcohol dehydrogenase to glycoaldehyde, which is then metabolized to glycolic, glyoxylic, and oxalic acids. These acids, along with excess lactic acid are responsible for the anion gap metabolic acidosis. Oxalic acid readily precipitates with calcium to form insoluble calcium oxalate crystals. Tissue injury is caused by widespread deposition of oxalate crystals and the toxic effects of glycolic and glyoxylic acids.

Mechanism of action

It has very good absorptive properties.

Mechanism of action

Tamsulosin is a blocker of alpha-1A and alpha-1D adrenoceptors. About 70% of the alpha-1 adrenoceptors in the prostate are of the alpha-1A subtype. By blocking these adrenoceptors, smooth muscle in the prostate is relaxed and urinary flow is improved. The blocking of alpha-1D adrenoceptors relaxes the detrusor muscles of the bladder which prevents storage symptoms. The specificity of tamsulosin focuses the effects to the target area while minimizing effects in other areas. Tamsulosin hydrochloride is a sulfamoylphenethylamine-derivative alpha1-adrenergic blocking agent. The drug is pharmacologically related to doxazosin, prazosin, and terazosin; however, unlike these drugs, tamsulosin has higher affinity and selectivity for alpha1A-adrenergic receptors, which are mainly located in nonvascular smooth muscle (eg, prostate), than for alpha1B-adrenergic receptors located in vascular smooth muscle (eg, internal iliac artery). Results of in vitro studies indicate that tamsulosin has 7-38 times greater affinity for alpha1A-adrenoceptors than for alpha1B-adrenoceptors; the drug has about 12 times greater affinity for alpha1-adrenergic receptors in the prostate than for those in the aorta. Such selectivity of tamsulosin for alpha1A-receptors may result in a reduced incidence of adverse cardiovascular effects (eg, syncope, dizziness, hypotension). On a molar basis, the alpha1-adrenergic receptor affinity of tamsulosin is about 6 times that of prazosin when tested in human prostatic tissue. Because of the prevalence of alpha-receptors on the prostate capsule, prostate adenoma, and bladder trigone and the relative absence of these receptors on the bladder body, alpha-adrenergic blocking agents decrease urinary outflow resistance in men. The symptoms associated with benign prostatic hyperplasia (BPH) are related to bladder outlet obstruction, which is comprised of two underlying components: static and dynamic. The static component is related to an increase in prostate size caused, in part, by a proliferation of smooth muscle cells in the prostatic stroma. However, the severity of BPH symptoms and the degree of urethral obstruction do not correlate well with the size of the prostate. The dynamic component is a function of an increase in smooth muscle tone in the prostate and bladder neck leading to constriction of the bladder outlet. Smooth muscle tone is mediated by the sympathetic nervous stimulation of alpha1 adrenoceptors, which are abundant in the prostate, prostatic capsule, prostatic urethra, and bladder neck. Blockade of these adrenoceptors can cause smooth muscles in the bladder neck and prostate to relax, resulting in an improvement in urine flow rate and a reduction in symptoms of BPH. The influence of (+/-)-tamsulosin, a selective alpha 1A-adrenoceptor antagonist, on the positive inotropic effect and the accumulation of inositol phosphates that are induced via alpha 1-adrenoceptors was studied in comparison with that of another alpha 1A-adrenoceptor ligand oxymetazoline in the rabbit ventricular myocardium. Phenylephrine elicited a concentration-dependent positive inotropic effect via alpha 1-adrenoceptors in the presence of either (+/-)-bupranolol or S(-)-timolol. The mode of antagonism induced by (+/-)-tamsulosin on the effect of phenylephrine was dependent or the concentration applied: (+/-)-tamsulosin at 1 and 3 nM acted in a competitive manner, the slope of the regression line of the Schild plot being unity and the pA2 value being 9.12; at 10 nM, it shifted further the concentration-response curve to the right without affecting the maximal response but the slope became less than unity. At 100 nM and higher, it suppressed the maximal response to phenylephrine. (+/-)-Tamsulosin effectively antagonized the positive inotropic effect of phenylephrine even after inactivation of alpha 1B-adrenoceptors by treatment with chlorethylclonidine, which is an indication that the (+/-)-tamsulosin-sensitive subtype belongs to a class resist

Pharmacodynamics

Tamsulosin is an alpha adrenoceptor blocker with specificity for the alpha-1A and alpha-1D subtypes, which are more common in the prostate and submaxillary tissue. The final subtype, alpha-1B, are most common in the aorta and spleen. Tamsulosin binds to alpha-1A receptors 3.9-38 times more selectively than alpha-1B and 3-20 times more selectively than alpha-1D. This selectivity allows for a significant effect on urinary flow with a reduced incidence of adverse reactions like orthostatic hypotension.