Betacin Cream

Indications

• Suppression of inflammatory disorders
• Management of allergic conditions
• Congenital adrenal hyperplasia
• Inflammatory and allergic eye conditions

Dosage

Children: For children aged 1–11 months: Initially 1 mg, repeated up to 4 times in 24 hours according to response. Aged 1–5 years: Initially 2 mg, repeated up to 4 times in 24 hours according to response. Aged 6–11 years: Initially 4 mg, repeated up to 4 times in 24 hours according to response. Aged 12–17 years: 4–20 mg, repeated up to 4 times in 24 hours according to response.

Adults: Dosage varies based on condition; typically, initial doses are adjusted according to the patient's response and severity of condition.

Mechanism of action

Betamethasone exerts its effects by binding to glucocorticoid receptors, leading to modulation of gene expression and suppression of inflammatory cytokines and mediators.

Pharmacodynamics

Betamethasone reduces inflammation and immune response, which is beneficial in managing various inflammatory and allergic disorders.

Pharmacokinetics

Betamethasone is rapidly absorbed after administration, with a long half-life allowing for once-daily dosing in many cases. It is metabolized in the liver and excreted primarily in urine.

Adverse effects

• Hiccups
• Oedema
• Mood and behaviour changes
• Vision disorders
• Serious gastro-intestinal effects
• Musculoskeletal effects
• Ophthalmic effects
• Stevens-Johnson syndrome
• Myocardial rupture (following recent myocardial infarction)

Interactions

• Cobicistat + betamethasone: Unknown (increases exposure)
• Idelalisib + betamethasone: Unknown (increases exposure)
• Clarithromycin + betamethasone: Unknown (increases exposure)

Precautions

• Immunosuppression due to prolonged corticosteroid treatment
• Adrenal suppression if given for longer than 3 weeks
• Increased susceptibility to infections, including chickenpox and measles

Pregnancy

Readily crosses the placenta. Transient effect on fetal movements and heart rate.

Storage

Store at room temperature, protect from light.

Formulations

• Betamethasone sodium phosphate 4 mg per 1 ml solution for injection ampoules

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

• Pain relief
• Anti-inflammatory treatment
• Antipyretic therapy
• Vitamin supplementation
• Antioxidant therapy

Dosage

Children: Refer to specific acid formulation and context for paediatric dosing. Consult BNF for Children for accurate dosing recommendations.

Adults: Refer to specific acid formulation and context for dosing. Consult relevant guidelines or BNF for precise dosing information.

Mechanism of action

Acids typically exert their effects by participating in biochemical reactions as proton donors. For example, in the case of acetylsalicylic acid, it inhibits the enzyme cyclooxygenase (COX), leading to a decrease in the synthesis of prostaglandins, which are mediators of inflammation and pain. This mechanism reduces inflammation, alleviates pain, and can lower fever. Other acids may act through different pathways, depending on their structure and target sites.

Pharmacodynamics

The pharmacodynamic properties of acids are variable and depend on the specific acid in question. Generally, they can modulate pH levels, influence metabolic pathways, and affect cellular signaling. For instance, ascorbic acid acts as an antioxidant, protecting cells from oxidative stress, and plays a role in collagen synthesis and immune function. The effects of acids can be dose-dependent and influenced by factors such as absorption, distribution, metabolism, and excretion.

Pharmacokinetics

The pharmacokinetics of acids varies widely depending on the specific compound. Generally, they are absorbed through the gastrointestinal tract, with some, like ascorbic acid, being actively transported. Distribution occurs via systemic circulation, with binding to plasma proteins varying among different acids. Metabolism typically involves conjugation and transformation into metabolites, which may retain therapeutic properties or be inactive. Excretion is primarily renal, with many acids being eliminated as free acids or conjugated forms.

Pregnancy

The use of acid-based medications during pregnancy should be approached with caution. Some acids may have teratogenic effects, while others may be safe. Consultation with a healthcare professional is advised.

Breast-feeding

Caution is advised when using acid-based medications during breastfeeding, as some acids may pass into breast milk and affect the infant. Consultation with a healthcare provider is recommended.

Storage

Store at room temperature, away from moisture and light. Specific storage conditions may vary depending on the type of acid.

Indications

• Eczema
• Psoriasis
• Contact dermatitis
• Seborrheic dermatitis
• Atopic dermatitis

Dosage

Children: Refer to the BNF for Children for appropriate dosing information.

Adults: Refer to relevant clinical guidelines or product information for specific dosing instructions.

Mechanism of action

Betamethasone dipropionate exerts its effects by binding to the glucocorticoid receptor, leading to the modulation of gene expression. This interaction results in the inhibition of pro-inflammatory cytokines, chemokines, and adhesion molecules, which reduces inflammation, suppresses the immune response, and promotes vasoconstriction in the affected tissues.

Pharmacodynamics

The pharmacodynamic effects of betamethasone dipropionate include a significant reduction in inflammation and immune response due to the inhibition of leukocyte infiltration at the site of inflammation. The drug also inhibits the release of arachidonic acid, subsequently decreasing the production of inflammatory mediators such as prostaglandins and leukotrienes. Its efficacy is enhanced by its high lipid solubility, allowing for better penetration through the skin layers.

Pharmacokinetics

Betamethasone dipropionate is well absorbed through the skin when applied topically. Its bioavailability is influenced by the formulation and the condition of the skin. The drug is metabolized primarily in the liver to inactive metabolites, which are excreted in the urine. The systemic absorption and effects are minimal when used as directed, but caution is advised in extensive applications or occlusive dressings, which may increase absorption.

Adverse effects

• Local skin atrophy
• Striae
• Telangiectasia
• Hypopigmentation
• Allergic contact dermatitis
• Systemic effects with prolonged use

Precautions

• Use with caution in patients with a history of diabetes mellitus
• Monitor for potential adrenal suppression with prolonged use
• Avoid application to infected areas unless treated

Pregnancy

Betamethasone dipropionate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Limited data suggest that topical corticosteroids have low systemic absorption.

Breast-feeding

Caution is advised when using betamethasone dipropionate during breastfeeding, as it is unknown whether it is excreted in breast milk. Topical corticosteroids should be applied sparingly and avoided on the breast area to minimize ingestion by the infant.

Storage

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

Formulations

• Topical cream
• Topical ointment
• Topical lotion

Indications

• Dry skin conditions
• Atopic dermatitis
• Psoriasis
• Eczema
• Skin hydration enhancement

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations based on age and condition.

Adults: Refer to the specific product monograph, as dosing may vary based on formulation and condition being treated.

Mechanism of action

Cetomacrogol acts as a surfactant, reducing the surface tension between different substances. This property facilitates the formation of emulsions and enhances the solubility of hydrophobic substances in aqueous solutions. By providing a barrier on the skin, it helps to prevent transepidermal water loss, thereby maintaining skin hydration.

Pharmacodynamics

The pharmacodynamic properties of cetomacrogol are characterized by its ability to improve the consistency and stability of emulsions, allowing for better delivery of topical agents. Its moisturizing effects help to alleviate symptoms associated with dry skin conditions, such as scaling, itching, and cracking.

Pharmacokinetics

Cetomacrogol is not systemically absorbed when applied topically, as it primarily acts at the site of application. Its pharmacokinetic profile is characterized by local action with minimal risk of systemic effects. Due to its emulsifying properties, it enhances the penetration of active ingredients in topical formulations without significant metabolic transformation.

Pregnancy

There are no known adverse effects in pregnancy. However, it is advisable to use only when clearly needed.

Breast-feeding

Cetomacrogol is generally considered safe to use during breastfeeding, but consult a healthcare professional before use.

Storage

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

Formulations

• Cream
• Ointment
• Emulsion

Indications

• Dry skin conditions
• Eczema
• Psoriasis
• Irritated or inflamed skin
• As a base in topical formulations

Dosage

Children: Refer to specific product guidelines for paediatric use.

Adults: Apply as needed as a topical formulation. Refer to specific product guidelines for details.

Mechanism of action

Cetostearyl alcohol acts primarily as an emollient and emulsifying agent. It forms a barrier on the skin's surface, which helps to retain moisture and prevent transepidermal water loss. As an emulsifier, it stabilizes oil-in-water mixtures, allowing for the uniform distribution of active ingredients in topical formulations. Its fatty alcohol structure contributes to its ability to soften and soothe the skin.

Pharmacodynamics

The pharmacodynamic properties of cetostearyl alcohol are primarily related to its emollient and emulsifying actions. By forming a protective barrier on the skin, it enhances the hydration and overall integrity of the skin barrier. It also contributes to the consistency and feel of topical formulations, which can improve patient adherence to treatment regimens.

Pharmacokinetics

Cetostearyl alcohol is not systemically absorbed when applied topically; it remains primarily on the skin surface to exert its effects. Due to its large molecular size and hydrophobic properties, it does not penetrate deeply into systemic circulation. The metabolism and excretion pathways are not well-defined due to its minimal systemic exposure.

Pregnancy

Cetostearyl alcohol is generally considered safe for use during pregnancy, but it is recommended to consult a healthcare professional.

Breast-feeding

Cetostearyl alcohol is unlikely to pose a risk to breastfeeding infants when used in topical formulations.

Storage

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

Formulations

• Creams
• Lotions
• Ointments
• Emulsions

Indications

• Topical antiseptic
• Preservative in pharmaceuticals
• Disinfectant

Dosage

Children: Refer to the BNF for Children for appropriate dosing recommendations, as pediatric doses can vary based on age, weight, and formulation.

Adults: For topical use, apply as needed to the affected area, ensuring it is clean and dry. Refer to specific product guidelines for concentration and formulation.

Mechanism of action

Chlorocresol acts as a potent activator of calcium (Ca2+) release from the sarcoplasmic reticulum in skeletal muscle, mediated by ryanodine receptors. It has been shown to facilitate Ca2+ release in cerebellar microsomes and in PC12 cells, demonstrating its ability to release Ca2+ from intracellular stores. The structural components of chlorocresol, particularly the chloro and methyl groups, are critical for this activation process, specifically targeting ryanodine receptor types 1 and 2.

Pharmacodynamics

The pharmacodynamics of chlorocresol involve its role as a calcium mobilizer within cells, enhancing intracellular calcium levels which can modulate various physiological processes. Its antiseptic properties are attributed to its ability to disrupt bacterial cell membranes, leading to cell lysis and death. This makes chlorocresol effective in controlling microbial growth in topical applications.

Pharmacokinetics

Chlorocresol is absorbed through the skin upon topical application. The extent of systemic absorption is influenced by formulation and concentration. It is metabolized in the liver, with metabolites excreted primarily through urine. The exact pharmacokinetic parameters, such as half-life and volume of distribution, are not well-documented in the literature.

Pregnancy

There is insufficient data on the safety of chlorocresol during pregnancy. Use cautiously and only if the benefits outweigh the risks.

Breast-feeding

Chlorocresol is excreted in breast milk. Caution is advised when administering to nursing mothers.

Storage

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

Formulations

• Topical solution
• Emulsions

Indications

• Severe infections caused by gram-negative bacteria
• Complicated urinary tract infections
• Bacterial sepsis
• Endocarditis caused by susceptible organisms

Dosage

Children: Dosing in children is also weight-based and varies by indication. Refer to the BNF for Children for specific dosing recommendations.

Adults: Dosage varies significantly based on the infection severity and type, renal function, and the specific bacterial susceptibility. Refer to clinical guidelines or the BNF for precise dosing.

Mechanism of action

Gram works by inhibiting bacterial protein synthesis. It binds to the 30S ribosomal subunit of the bacteria, causing misreading of the mRNA and ultimately preventing the synthesis of essential proteins necessary for bacterial growth and replication.

Pharmacodynamics

The pharmacodynamics of Gram include its bactericidal activity against susceptible bacteria. The drug shows concentration-dependent killing, meaning that higher drug concentrations correlate with greater bactericidal effects. The post-antibiotic effect is noted, where bacterial growth is inhibited even after the drug concentration falls below the minimum inhibitory concentration (MIC).

Pharmacokinetics

Gram is usually administered parenterally (intravenously or intramuscularly), and its absorption can vary based on the route of administration. It is distributed widely in body fluids and tissues, although it does not penetrate well into the central nervous system. The drug is primarily eliminated through the kidneys, and its half-life may be prolonged in patients with renal impairment. Monitoring of drug levels may be necessary to avoid toxicity.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Allergic reactions
• Rash
• Renal dysfunction

Precautions

• Use with caution in patients with renal impairment
• Monitor renal function during therapy
• Assess for potential allergic reactions

Pregnancy

Use only if the potential benefit justifies the potential risk to the fetus. Consult with a healthcare provider.

Breast-feeding

Use with caution, as it may be excreted in breast milk. Consult with a healthcare provider.

Storage

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

Indications

• Solvent in pharmaceutical formulations
• Moisturizer and humectant in topical applications
• Potential use in the management of drug solubility issues

Dosage

Children: Refer to specific formulations and clinical guidelines, as dosing varies widely based on the application and formulation.

Adults: Refer to specific formulations and clinical guidelines, as dosing varies widely based on the application and formulation.

Mechanism of action

Glycols, particularly propylene glycol, act as humectants, which help to retain moisture in formulations. They can also enhance the solubility of drugs, aiding in their absorption when used as excipients. Propylene glycol is metabolized in the liver to lactate and subsequently to glucose, providing a source of energy when utilized in metabolic pathways.

Pharmacodynamics

The pharmacodynamics of glycols involve their ability to modulate the viscosity of solutions and enhance the solubility of other compounds. Propylene glycol can also facilitate the absorption of other drugs when used in formulations. It exhibits a low toxicity profile when used appropriately, but excessive systemic exposure can lead to metabolic acidosis and other adverse effects.

Pharmacokinetics

Glycols are rapidly absorbed when administered intravenously or orally. Propylene glycol is metabolized primarily in the liver, with a half-life varying based on the dose and individual metabolism. Renal excretion plays a role in the elimination of metabolites. Accumulation can occur in individuals with impaired liver or kidney function, necessitating careful monitoring of dosing in such populations.

Pregnancy

The safety of glycol in pregnancy is not well established. Consult healthcare professionals before use.

Breast-feeding

Glycol's effects during breastfeeding are not well characterized. Caution is advised.

Storage

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

Indications

• Vision correction
• Phototherapy for skin conditions (e.g., psoriasis, eczema)
• Treatment of seasonal affective disorder (SAD)
• Circadian rhythm disorders
• Wound healing

Dosage

Children: Light therapy for paediatric patients should be approached with caution and always under professional guidance. Specific dosages will depend on the individual treatment protocol and condition being addressed.

Adults: Dosage of light therapy varies based on the condition being treated and should be tailored to individual needs, typically ranging from 15 minutes to 2 hours of exposure per day depending on the specific treatment protocol.

Mechanism of action

Light affects biological systems primarily through phototransduction, which involves the conversion of light into electrical signals within photoreceptor cells in the retina. This process initiates a cascade of biochemical reactions that ultimately lead to visual perception. In addition, specific wavelengths of light can interact with various biological molecules, triggering cellular responses such as the production of vitamin D through skin exposure to UVB radiation.

Pharmacodynamics

The pharmacodynamic effects of light are highly dependent on its wavelength and intensity. Short-wavelength blue light (around 480 nm) is known to influence circadian rhythms by affecting melatonin secretion. In therapeutic settings, light can modulate biological responses, such as promoting wound healing, reducing inflammation, and alleviating symptoms of seasonal affective disorder (SAD) through bright light therapy.

Pharmacokinetics

Light does not undergo traditional pharmacokinetic processes such as absorption, distribution, metabolism, or excretion. Instead, its effects are immediate and localized, depending on the intensity and duration of exposure. The penetration depth of light varies with wavelength; for example, UV light can penetrate the skin and affect deeper tissues, while visible light primarily affects the surface layers.

Pregnancy

There is limited data on the effects of light exposure during pregnancy. However, excessive exposure to bright light can be harmful to both the mother and the developing fetus.

Breast-feeding

Light exposure is generally considered safe while breastfeeding, but excessive exposure should be avoided to prevent potential harm to the infant.

Storage

Light should be properly controlled and managed in environments where it is used, ensuring that exposure levels are safe and effective.

Indications

• Insecticide for agricultural use
• Research tool in toxicology

Dosage

Children: Refer to the BNF for Children for specific dosing and administration guidelines.

Adults: Refer to the BNF for specific dosing and administration guidelines.

Mechanism of action

Methyl parathion acts primarily by inhibiting the enzyme acetylcholinesterase, which is essential for the breakdown of the neurotransmitter acetylcholine. Its active metabolite, methyl paraoxon, is a potent inhibitor of both acetylcholinesterase and butyrylcholinesterase. The inhibition of these enzymes results in the accumulation of acetylcholine at synapses, leading to overstimulation of cholinergic receptors and resultant toxic effects.

Pharmacodynamics

The pharmacodynamics of methyl parathion involve its action as a noncompetitive inhibitor of acetylcholinesterase, causing prolonged effects of acetylcholine due to its inability to be hydrolyzed. The resultant cholinergic toxicity can lead to symptoms such as muscle twitching, respiratory distress, and potentially fatal outcomes if not treated promptly. The extent of inhibition is dose-dependent, with significant toxicity occurring after substantial enzyme inhibition.

Pharmacokinetics

Methyl parathion is absorbed through the gastrointestinal tract and can also be absorbed through the skin and respiratory tract. It is metabolized in the liver to form methyl paraoxon, which is responsible for the majority of its toxic effects. The distribution of methyl parathion in body tissues is influenced by its lipophilicity, and it is primarily excreted as metabolites in the urine. The elimination half-life and specific pharmacokinetic parameters can vary based on individual metabolism and exposure levels.

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether this drug is excreted in human milk. Caution is advised when administering to nursing women.

Storage

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

Formulations

• Liquid formulation

Indications

• Constipation
• Dry skin
• Skin irritation

Dosage

Children: Refer to specific guidelines and prescribing information for paediatric dosing.

Adults: Refer to specific guidelines and prescribing information for adult dosing.

Mechanism of action

Paraffin acts as a lubricating agent in the gastrointestinal tract. It coats the stool and the intestinal walls, which helps to ease the passage of feces by reducing friction. This action promotes bowel movements and alleviates constipation. When used topically, it forms a barrier on the skin, which helps to retain moisture and protect against irritants.

Pharmacodynamics

Paraffin has a low viscosity and surface tension, which allows it to spread easily over surfaces. Its lubricating properties facilitate the movement of stool through the intestines, while its emollient properties help in maintaining skin hydration and barrier function. The onset of action for oral administration typically occurs within 6 to 8 hours, making it effective in treating occasional constipation.

Pharmacokinetics

Paraffin is not absorbed systemically when ingested; it remains in the gastrointestinal tract and is excreted unchanged in the feces. After oral administration, it acts locally in the intestines without significant systemic effects. When used topically, it remains on the skin surface and does not penetrate deeply, providing a protective layer without altering systemic pharmacokinetics.

Adverse effects

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting
• Lipid pneumonia (when aspirated)
• Electrolyte imbalances

Precautions

• Use with caution in patients with gastrointestinal obstruction
• Avoid in patients with a history of aspiration
• Monitor for signs of dehydration with prolonged use

Pregnancy

Use only if clearly needed. Consult a healthcare provider for advice.

Breast-feeding

Paraffin can be excreted in breast milk, use with caution.

Storage

Store at room temperature away from moisture and heat.

Formulations

• Liquid paraffin
• Soft paraffin (for topical use)

Indications

• Hypophosphatemia
• Calcium phosphate deficiency
• Nutritional supplementation
• pH adjustment in pharmaceutical formulations

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on indication.

Adults: Refer to clinical guidelines or BNF for specific dosing recommendations based on indication.

Mechanism of action

Phosphoric acid provides phosphate ions that are critical for numerous biochemical reactions in the body. These phosphate ions are involved in the formation of ATP, which is essential for energy transfer within cells. The acid itself dissociates in aqueous solutions, releasing hydrogen ions and contributing to pH levels, which can affect enzymatic activities and cellular functions.

Pharmacodynamics

Phosphoric acid acts by replenishing phosphate levels in the body, which can be important in various physiological processes including energy metabolism, bone mineralization, and the synthesis of nucleic acids. Its effects on pH regulation can also influence metabolic pathways, particularly in managing acidosis or alkalosis.

Pharmacokinetics

Phosphoric acid is generally administered orally or intravenously, depending on the therapeutic application. Following administration, it is absorbed in the gastrointestinal tract, with phosphate ions distributed throughout the body. The kidneys play a significant role in regulating phosphate homeostasis, with excess phosphate being excreted in urine. The half-life of phosphoric acid is not well defined, as it is rapidly metabolized and utilized in various metabolic pathways.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Hypophosphatemia

Precautions

• Use with caution in patients with renal impairment
• Monitor phosphate levels in patients receiving long-term therapy
• Consider potential for gastrointestinal irritation

Pregnancy

Phosphoric acid is generally considered safe in pregnancy when used in recommended doses, but caution is advised.

Breast-feeding

Phosphoric acid is excreted in breast milk, use with caution and under medical supervision.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Oral solutions
• Tablets
• Syrups

Indications

• Plant growth regulation
• Agricultural applications as a growth inhibitor

Dosage

Children: Not applicable.

Adults: Refer to the relevant agricultural guidelines for specific applications.

Mechanism of action

In an in vitro study, propylene acts as a plant growth inhibitor by inhibiting the oxidation of indole-3-acetic acid by peroxidase in the presence of superoxide anion radicals. This inhibition is linked to the activation of an iron complex (compound III) shuttle, which enhances the reaction rate between superoxide and peroxidase, ultimately affecting plant growth processes. Propylene is a less effective inhibitor compared to ethylene.

Pharmacodynamics

The pharmacodynamic effects of propylene are primarily observed in its role as a growth inhibitor in plants. By modulating the oxidation of phytohormones like indole-3-acetic acid, propylene can influence various growth responses in plants, potentially affecting processes such as cell elongation and division.

Pharmacokinetics

Information on the pharmacokinetics of propylene in humans is not well-documented, as its primary uses are industrial and agricultural. Its metabolism may be influenced by environmental factors, and its effects are primarily studied in the context of plant biology rather than human pharmacology.

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.

Dosage

Children: Refer to specific product information for dosing guidelines.

Adults: Refer to specific product information for dosing guidelines.

Pregnancy

Consult a healthcare professional before use. The effects of Soft during pregnancy are not well-documented.

Breast-feeding

Consult a healthcare professional before use. The safety of Soft during breastfeeding is not well-established.

Storage

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

Dosage

Children: Refer to the BNF for Children for appropriate paediatric dosing information.

Adults: Refer to the specific BNF guidelines for dosing information as it may vary based on the condition being treated.

Mechanism of action

The mechanism of action for White involves its interaction with specific biological pathways, leading to the desired pharmacological effects. The precise pathways may include modulation of receptor activity or alteration of enzyme function, although specific details are not provided.

Pharmacodynamics

Pharmacodynamics of White includes its effects on the body, including therapeutic effects and potential side effects. As a compound, it may exert its influence on multiple physiological systems, which can lead to changes in symptoms or disease progression.

Pharmacokinetics

Pharmacokinetics of White involves its absorption, distribution, metabolism, and excretion. Understanding these parameters can help predict how the drug behaves in the body, including onset of action and duration of effect. Detailed pharmacokinetic data is not specified.

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

Glucocorticoids inhibit neutrophil apoptosis and demargination, and inhibit NF-Kappa B and other inflammatory transcription factors. They also inhibit phospholipase A2, leading to decreased formation of arachidonic acid derivatives. In addition, glucocorticoids promote anti-inflammatory genes like interleukin-10. Corticosteroids like betamethasone can act through nongenomic and genomic pathways. The genomic pathway is slower and occurs when glucocorticoids activate glucocorticoid receptors and initiate downstream effects that promote transcription of anti-inflammatory genes including phosphoenolpyruvate carboxykinase (PEPCK), IL-1-receptor antagonist, and tyrosine amino transferase (TAT). On the other hand, the nongenomic pathway is able to elicit a quicker response by modulating T-cell, platelet and monocyte activity through the use of existing membrane-bound receptors and second messengers. Corticosteroids interact with specific receptor proteins in target tissues to regulate the expression of corticosteroid responsive genes, thereby changing the levels and array of proteins synthesized by the various target tissues. As a consequence of the time required for changes in gene expression and protein synthesis, most effects of corticosteroids are not immediate, but become apparent after several hours. ... Although corticosteroids predominantly act to increase expression of target genes, there are well documented examples where glucocorticoids decrease transcription of target genes ... In contrast to these genomic effects, recent studies have raised the possibility that some actions of corticosteroids are immediate and are mediated by membrane-bound receptors. /Adrenocorticosteroids/ The mechanisms by which glucocorticoids inhibit glucose utilization in peripheral tissues are not fully understood. Glucocorticoids decrease glucose uptake in adipose tissue, skin, fibroblasts, thymocytes, and polymorphonuclear leukocytes; these effects are postulated to result from translocation of the glucose transporters from the plasma membrane to an intracellular location. These peripheral effects are associated with a number of catabolic actions, including atrophy of lymphoid tissue, decreased muscle mass, negative nitrogen balance, and thinning of the skin. /Adrenocorticalsteroids/ The mechanisms by which the glucocorticoids promote gluconeogenesis are not fully defined. Amino acids mobilized from a number of tissues in response to glucocorticoids reach the liver and provide substrate for the production of glucose and glycogen. In the liver, glucocorticoids induce the transcription of a number of enzymes involved in gluconeogenesis and amino acid metabolism, including phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and fructose-2,6-bisphosphatase. Analyses of the molecular basis for regulation of phosphoenolpyruvate carboxykinase gene expression have identified complex regulatory influences involving an interplay among glucocorticoids, insulin, glucagon, and catecholamine. The effects of these hormones and amines on phosphoenolpyruvate carboxykinase gene expression mirror the complex regulation of gluconeogenesis in the intact organism. /Adrenocorticalsteroids/ ... /A/ major action of corticosteroids on the cardiovascular system is to enhance vascular reactivity to other vasoactive substances. Hypoadrenalism generally is associated with hypotension and reduced response to vasoconstrictors such as norepinephrine and angiotensin II. This diminished pressor response is explained partly by recent studies in experimental systems showing that glucocorticoids increase expression of adrenergic receptors in the vascular wall. Conversely, hypertension is seen in patients with excessive glucocorticoid secretion, occurring in most patients with Cushing's syndrome and in a subset of patients treated with synthetic glucocorticoids (even those lacking any significant mineralocorticoid action). /Adrenocorticosteroids/ For more Mechanism of Action (

Pharmacodynamics

Corticosteroids bind to the glucocorticoid receptor inhibiting pro-inflammatory signals, while promoting anti-inflammatory signals. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients who require long-term treatment with a corticosteroid should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections.

Mechanism of action

...In skeletal muscle sarcoplasmic reticulum, 4-chloro-m-cresol was found to be a potent activator of Ca2+ release mediated by a ruthenium red/caffeine-sensitive Ca2+ release channel. In cerebellar microsomes, this compound released Ca2+ from an inositol-1,4,5-trisphosphate-insensitive store, suggesting that there too it was acting at the ryanodine receptor level. When tested on PC12 cells, chlorocresol released Ca2+ from a caffeine- and thapsigargin-sensitive intracellular store. In addition, the compound was capable of releasing Ca2+ after pretreatment of PC12 cells with bradykinin, suggesting that it acts on a channel contained within an intracellular Ca2+ store that is distinct from that sensitive to inositol-1,4,5-trisphosphate. Structure-activity relationship analyses suggest that the chloro and methyl groups in chlorocresols are important for the activation of the ryanodine receptor Ca2+ release channel. The ryanodine receptor type 1 (RyR1) and type 2 (RyR2), but not type 3 (RyR3), are efficiently activated by 4-chloro-m-cresol (4-CmC). /It was/ previously /shown/ that a 173-amino acid segment of RyR1 (residues 4007-4180) is required for channel activation by 4-CmC ... present study... used site-directed mutagenesis to identify individual amino acid(s) within this region that mediate 4-CmC activation. In RyR1, substitution of 11 amino acids conserved between RyR1 and RyR2, but divergent in RyR3, with their RyR3 counterparts reduced 4-CmC sensitivity to the same degree as substitution of the entire 173-amino acid segment. Further analysis of various RyR1 mutants containing successively smaller numbers of these mutations identified 2 amino acid residues (Gln(4020) and Lys(4021)) that, when mutated to their RyR3 counterparts (Leu(3873) and Gln(3874)), abolished 4-CmC activation of RyR1. Mutation of either of these residues alone did not abolish 4-CmC sensitivity, although Q4020L partially reduced 4-CmC-induced Ca /ion/ transients. In addition, mutation of the corresponding residues in RyR3 to their RyR1 counterparts (L3873Q/Q3874K) imparted 4-CmC sensitivity to RyR3. Recordings of single RyR1 channels indicated that 4-CmC applied to either the luminal or cytoplasmic side activated the channel with equal potency. Secondary structure modeling in the vicinity of the Gln(4020)-Lys(4021) dipeptide suggests that the region contains a surface-exposed region adjacent to a hydrophobic segment, indicating that both hydrophilic and hydrophobic regions of RyR1 are necessary for 4-CmC binding to the channel and/or to translate allosteric 4-CmC binding into channel activation.

Mechanism of action

Acute poisoning ... is related to ... inhibiting action on enzyme acetylcholinesterase. Toxic manifestations generally occur only after more than 50% of plasma cholinesterase is inhibited. ... Methyl parathion ... depend on oxidative activation by replacement of thiono-sulfur with oxygen for ... toxicity. Methyl parathion has only a slight inhibitory action on acetylcholinesterase and butyrylcholinesterase, but its active metabolite, methyl paraoxon, is a potent inhibitor of both these enzymes. A study was conducted examining the inhibition of (Ca2+ and Mg2+)-ATPase by parathion (56382) and methyl parathion. Enzyme activity was assessed spectrophotometrically in pig erythrocyte membranes containing calcium2+ (Ca2+) and magnesium2+ and in solubilized membrane preparations incubated with the test agents. The enzyme response to ATP was biphasic. Equations expressing the kinetics of the substrate curves described two classes of the ATP binding active site, one with high affinity and low maximum rate and one with low affinity and high maximum rate. High affinity active sites were stimulated by low ATP concentrations (20 uM), whereas low affinity active sites were stimulated by high ATP levels (2 mM). Parathion and methylparathion dose dependently inhibited enzyme activity; parathion had a greater inhibitory effect than methylparathion. Lineweaver-Burke and Dixon plots indicated noncompetitive inhibition. Parathion and methylparathion induced enzyme inhibition occurred over a range of free calcium ion concentrations (0.5 to 5 mM); the inhibition was significantly greater at lower Ca2+ concentrations (1 to 100 uM) than at higher concentrations. The authors conclude that parathion and methylparathion inhibit ATPase activity by binding to a site on the enzyme rather than through an interaction with associated lipids. For more Mechanism of Action (Complete) data for METHYL PARATHION (6 total), please visit the HSDB record page.

Mechanism of action

In an in vitro study of the mechanism of action of ethylene as a plant growth inhibitor, the effects of ethylene and some of its analogs, including propylene, on the oxidation of indole-3-acetic acid were examined. Ethylene and its analogs inhibited the oxidation of indole-3-acetic acid by peroxidase under conditions where the iron complex (compound III, an oxy-ferrous complex of peroxidase) shuttle was activated. Inhibition occurred only in the presence of the superoxide anion radical 02(-). Spectral and kinetic data indicated that ethylene and its analogs enhanced the rate of reaction of 02(-) with peroxidase; ie, the iron complex (compound III) shuttle, resulting in the formation of compound III. Propylene was a less effective inhibitor than ethylene.