SUPYRA DISPERSIBLE

Indications

• Malaria caused by Plasmodium species
• Toxoplasmosis, particularly in immunocompromised patients
• Adjunct treatment of autoimmunity-related conditions

Dosage

Adults: For the treatment of toxoplasmosis in adults, the recommended dosage is 50 mg once daily until delivery, usually in combination with sulfadiazine and

Mechanism of action

Pyrimethamine inhibits the dihydrofolate reductase enzyme in plasmodia, blocking the biosynthesis of purines and pyrimidines necessary for DNA synthesis and cell multiplication. This inhibition leads to failure in nuclear division during the formation of schizonts in erythrocytes and liver. Additionally, it has immunomodulatory effects by increasing oxidative stress, which may aid in the elimination of parasites.

Pharmacodynamics

As an antiparasitic compound, pyrimethamine is particularly effective against uncomplicated, chloroquine-resistant Plasmodium falciparum malaria and Toxoplasma gondii. It exhibits blood schizonticidal activity and some tissue schizonticidal effects, though it does not affect gametocytes. The selective toxicity towards parasites, contrasted with minimal effects on human cells, is due to differences in nucleic acid precursor requirements. Its effectiveness is notably enhanced when used in combination with sulfonamides.

Pharmacokinetics

Pyrimethamine is absorbed well after oral administration and undergoes hepatic metabolism. Its elimination half-life is variable but can be prolonged in cases of renal impairment. The drug is primarily excreted in urine, both as unchanged drug and metabolites. Caution is advised in patients with liver and renal impairment, and monitoring of blood counts is recommended during prolonged therapy due to the risk of haematological toxicity.

Contra-indications

• G6PD deficiency
• Severe renal impairment
• Severe hepatic impairment
• History of seizures
• Heart block (requires ECG monitoring during parenteral treatment)

Adverse effects

• Abdominal pain
• Agitation
• Agranulocytosis
• Anaemia
• Angioedema
• Asthma
• Diarrhoea
• Dizziness
• Fever
• Flushing
• Headache
• Hearing impairment
• Hypersensitivity reactions
• Loss of consciousness
• Muscle weakness
• Nausea
• Skin reactions
• Thrombocytopenia
• Tinnitus
• Vertigo
• Vomiting

Interactions

• Antiepileptics (increases risk of haematological toxicity)
• Fosphenytoin (increases risk of haematological toxicity)
• Phenytoin (increases risk of haematological toxicity)
• Phenobarbital (increases risk of haematological toxicity)
• Primidone (increases risk of haematological toxicity)
• Methotrexate (increases risk of adverse effects)
• Pemetrexed (increases risk of adverse effects)

Precautions

• Monitor blood counts during prolonged treatment
• Consider dose reduction in renal and hepatic impairment
• Caution in patients predisposed to folate deficiency
• Avoid large loading doses in patients with a history of seizures
• Use with caution in pregnancy (theoretical teratogenic risk in the first trimester)

Pregnancy

High doses are teratogenic in the first trimester; however, in malaria, the benefit of treatment may outweigh the risks.

Breast-feeding

Present in milk but not known to be harmful; adequate folate supplements should be given to the mother. Avoid breastfeeding during treatment of toxoplasmosis.

Storage

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

Formulations

• Daraprim 25 mg tablets
• Oral suspension

Indications

• Cerebral edema
• Elevated intracranial pressure
• Acute kidney injury
• Oliguria
• Glaucoma
• Renal function diagnostic aid

Dosage

Adults: For cerebral edema, administer 0

Mechanism of action

Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma. This action reduces cerebral edema and intracranial pressure. As a diuretic, it increases the osmolality of glomerular filtrate, leading to increased urinary excretion of water and preventing sodium and chloride reabsorption in the renal tubules. Mannitol also facilitates the urinary excretion of toxic substances and can help in assessing renal function by measuring glomerular filtration rate (GFR).

Pharmacodynamics

Mannitol is classified as an osmotic diuretic. It is chemically similar to other sugar alcohols but has a unique ability to promote diuresis by remaining unabsorbed in the renal tubules. Its use is indicated for conditions associated with increased body fluids, such as cerebral edema and glaucoma. Mannitol may be combined with other diuretics to enhance diuretic efficacy. Inhaled formulations are used in cystic fibrosis, though they may cause bronchospasm and hemoptysis.

Pharmacokinetics

Mannitol is freely filtered by the glomeruli with less than 10% tubular reabsorption, which allows for its urinary excretion rate to serve as a measurement of GFR. It does not undergo significant metabolism and is eliminated primarily through the kidneys. The onset of action occurs within 30 to 60 minutes after intravenous administration, with effects lasting for several hours. Administration may require monitoring of renal function and fluid balance.

Contra-indications

• Anuria
• Severe dehydration
• Severe renal impairment
• Intracranial bleeding

Adverse effects

• Asthenia
• Gastrointestinal disturbances
• Dry mouth
• Confusion
• Visual impairment
• Hypotension
• Electrolyte imbalances
• Pulmonary edema
• Hemoptysis (with inhalation use)
• Bronchospasm (with inhalation use)

Interactions

• Potassium-sparing diuretics may increase the risk of hyperkalemia
• Other diuretics may have additive effects
• Caution with nephrotoxic agents

Precautions

• Caution in patients with diabetes mellitus
• Caution in the elderly
• Caution in patients with gout
• Caution in patients with hepatic impairment
• Monitor renal function and electrolytes regularly
• May cause blue fluorescence of urine

Pregnancy

Manufacturer advises avoid due to potential toxicity in animal studies.

Breast-feeding

Manufacturer advises avoid due to lack of information available.

Storage

Store in a cool, dry place, away from light. Do not freeze.

Formulations

• Solution for injection
• Inhalation powder
• Oral solution

Indications

• Malaria caused by Plasmodium falciparum
• Rheumatoid arthritis
• Lupus erythematosus

Mechanism of action

The exact mechanism of action of amodiaquine is not completely understood. It is believed to inhibit heme polymerase activity, leading to an accumulation of free heme, which is toxic to malarial parasites. Amodiaquine binds to free heme, preventing its conversion to a less toxic form, and this drug-heme complex disrupts membrane function within the parasite. Additionally, it may interfere with protein synthesis by binding to nucleoproteins and intercalating into double-stranded DNA, inhibiting DNA and RNA polymerase. Furthermore, it is known to concentrate in the digestive vacuoles of the parasites, increasing vacuolar pH and impairing the parasite's ability to metabolize hemoglobin.

Pharmacodynamics

Amodiaquine is effective against malaria and exhibits anti-inflammatory properties. It can depress cardiac muscle function, impair conduction, and produce vasodilation, which may lead to hypotension. Other side effects include respiratory depression, diplopia, dizziness, and nausea. While its effectiveness is comparable to that of chloroquine, the development of resistance to amodiaquine has been documented. The drug's adverse effects and potential for toxicity necessitate monitoring during treatment.

Pharmacokinetics

Amodiaquine is well absorbed after oral administration. It undergoes hepatic metabolism, with its active metabolite contributing to its antimalarial effects. The pharmacokinetics can be influenced by factors such as hepatic function and concurrent medications. The elimination half-life of amodiaquine may vary, and it is important to consider individual patient factors when determining dosing regimens.

Contra-indications

• Hypersensitivity to amodiaquine or any of its components
• Severe liver impairment
• History of retinopathy related to 4-aminoquinoline derivatives
• Severe hematological disorders, including agranulocytosis and aplastic anemia

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Dizziness
• Diplopia
• Hypotension
• Cardiac arrhythmias
• Hepatotoxicity
• Skin rashes
• Agranulocytosis

Interactions

• May enhance effects of anticoagulants
• Concomitant use with other antimalarials may increase risk of toxicity
• Caution with drugs that can cause hepatotoxicity
• May affect the metabolism of drugs that are substrates for CYP450 enzymes

Precautions

• Monitor liver function during treatment
• Use with caution in patients with a history of cardiovascular disease
• Assess for signs of hematological disorders
• Consider potential for cross-resistance with other 4-aminoquinoline derivatives

Pregnancy

Amodiaquine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. It is advised to refer to local guidelines.

Breast-feeding

Amodiaquine is excreted in breast 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.

Formulations

• Tablets
• Oral suspension

Indications

• Metabolic acidosis
• Acid-base imbalance
• Urinary alkalinization
• Treatment of certain poisonings
• Cardiac arrest in the context of metabolic acidosis

Dosage

Children: Refer to the BNF for Children for specific pediatric dosages, as they depend on the clinical condition

Adults: Refer to local guidelines and BNF for specific dosing recommendations as they may vary based on clinical condition and severity. General adult dosing for bicarbonate may range from 1 to 2 mEq/kg IV initially, followed by maintenance doses as needed.

Mechanism of action

Bicarbonate acts as a buffer that neutralizes excess acids in the body. It dissociates in solution to produce bicarbonate ions (HCO3-) which can react with hydrogen ions (H+) to form carbonic acid (H2CO3), subsequently leading to the production of carbon dioxide (CO2) and water (H2O). This process helps to raise the pH of the blood and other fluids, counteracting acidosis. Bicarbonate is involved in several metabolic pathways, including the urea cycle and various biosynthetic pathways.

Pharmacodynamics

Bicarbonate's primary pharmacodynamic effect is its ability to buffer hydrogen ions, thus increasing blood pH. This is essential in conditions such as metabolic acidosis, where the body accumulates excess acid. By raising blood pH, bicarbonate can help alleviate symptoms associated with acidemia, such as fatigue, confusion, and shortness of breath. Its effects can also influence the renal and respiratory systems to regulate acid-base homeostasis.

Pharmacokinetics

Bicarbonate is rapidly absorbed from the gastrointestinal tract. It is distributed throughout the body fluids, and its effects can be seen within minutes of administration. The kidneys play a significant role in bicarbonate homeostasis by reabsorbing bicarbonate from urine and excreting hydrogen ions. The elimination half-life can vary, depending on the patient's metabolic state and renal function.

Pregnancy

Use with caution. Consult with a healthcare provider before use.

Breast-feeding

Use with caution. Consult with a healthcare provider before use.

Storage

Store in a cool, dry place away from light.

Indications

• Acidulant in food and beverages
• Preservative in pharmaceutical formulations
• pH adjuster in various chemical preparations

Dosage

Children: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Adults: Refer to product-specific guidelines for appropriate dosing based on formulation and indication.

Mechanism of action

Citric acid acts by chelating metal ions, which can enhance the solubility of certain compounds and improve their bioavailability. It also contributes to the acidity of the environment, which can influence enzymatic activity and metabolic pathways, particularly in the degradation of citronellol.

Pharmacodynamics

Citric acid exhibits mild pharmacological effects primarily attributed to its role in metabolic processes. It aids in the regulation of pH levels, which can impact enzymatic reactions and biochemical pathways. The acid's chelating properties may help to reduce the toxicity of certain metal ions in biological systems.

Pharmacokinetics

Citric acid is rapidly absorbed after oral administration and is metabolized in the liver. It undergoes conversion to various metabolites in the citric acid cycle, contributing to energy production. The elimination primarily occurs through urine, with minimal accumulation in the body.

Pregnancy

Citric acid is generally regarded as safe during pregnancy when used in food amounts. However, consult a healthcare provider for advice on medicinal use.

Breast-feeding

Citric acid is considered safe during breastfeeding when consumed in food amounts. For medicinal use, consult a healthcare provider.

Storage

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

Indications

• Hypovolemic shock
• Severe burns
• Postoperative fluid replacement
• Sepsis
• Trauma management

Dosage

Children: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Adults: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Mechanism of action

Colloidal solutions work by maintaining oncotic pressure in the blood, thus helping to retain fluid within the vascular system. This is primarily due to the large molecular weight of the colloidal particles, which cannot easily pass through capillary walls. The presence of colloids in the blood helps to draw water into the circulation, increasing blood volume and improving tissue perfusion.

Pharmacodynamics

The pharmacodynamics of colloidal solutions are centered on their ability to exert osmotic pressure, which helps maintain blood volume and pressure. This effect is particularly important in conditions such as hypovolemia and shock, where fluid replacement is necessary to restore hemodynamic stability. The efficacy of colloidal solutions can vary depending on the type of colloid used, as well as the underlying clinical condition being treated.

Pharmacokinetics

Colloidal solutions are typically administered intravenously and their pharmacokinetics can vary based on the specific formulation. Generally, colloids are distributed throughout the vascular compartment and have a longer duration of action compared to crystalloids, as they remain in circulation longer. The elimination of colloids is primarily through the reticuloendothelial system, where they are metabolized or eliminated by the liver and spleen. Factors such as particle size and composition can influence their distribution and clearance.

Adverse effects

• Allergic reactions
• Injection site reactions
• Nausea
• Vomiting
• Headache
• Fever

Precautions

• Use with caution in patients with known allergies to any component of the formulation
• Monitor for signs of hypersensitivity during administration
• Consider volume overload in patients with cardiac or renal impairment

Pregnancy

The safety of colloidal solutions during pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether colloidal solutions are excreted in human milk. Caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, protect from light, and do not freeze. Keep out of reach of children.

Formulations

• Colloidal silver
• Colloidal gold
• Colloidal iron
• Other metal colloids

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

• Used as an excipient in solid dosage forms
• Facilitates drug disintegration and dissolution

Dosage

Children: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Adults: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Mechanism of action

Crospovidone acts by rapidly absorbing water and swelling upon contact with moisture. This action leads to the disintegration of solid dosage forms, thus increasing the surface area of the active ingredients and promoting their dissolution and subsequent absorption in the gastrointestinal tract. It does not affect the pH of the formulation, ensuring that the active ingredients remain stable.

Pharmacodynamics

Crospovidone exhibits properties that enhance the bioavailability of active ingredients in pharmaceutical formulations. Its ability to rapidly disintegrate tablets and capsules leads to quicker release and absorption of the drug into systemic circulation. As a disintegrant, it aids in the effective delivery of drugs that may otherwise be poorly soluble.

Pharmacokinetics

Crospovidone itself is not absorbed systemically when administered orally. It remains in the gastrointestinal tract, where it performs its function as a disintegrant. The pharmacokinetic profile of drugs formulated with crospovidone may be influenced by the enhanced dissolution and absorption rates provided by this excipient.

Pregnancy

Crospovidone is considered to have low toxicity and is generally regarded as safe for use during pregnancy, but specific studies are limited.

Breast-feeding

There is insufficient data on the excretion of crospovidone in human milk, but it is deemed safe for use during breastfeeding.

Storage

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

Formulations

• Powder
• Tablets

Indications

• To enhance the palatability of oral medications
• To improve compliance in pediatric patients
• To mask unpleasant tastes of active pharmaceutical ingredients

Dosage

Children: Refer to specific formulations for guidance, as flavoring agents are typically used in very small quantities and are not dosed independently.

Adults: Refer to specific formulations for guidance, as flavoring agents are typically used in very small quantities and are not dosed independently.

Mechanism of action

Flavor compounds act primarily by stimulating taste receptors on the tongue, which can enhance the overall sensory experience of ingesting a product. Certain flavor compounds may also interact with olfactory receptors, contributing to the perception of flavor through smell. The stimulation of these receptors can lead to increased salivation and improved swallowing.

Pharmacodynamics

The use of flavoring agents in pharmaceuticals can influence compliance, particularly in children and individuals who may have difficulty swallowing pills. By enhancing the taste of a medication, these agents can reduce gag reflex and aversion, potentially improving therapeutic outcomes. However, the pharmacodynamic effects are largely dependent on the individual's taste preferences and sensitivities.

Pharmacokinetics

The pharmacokinetics of flavoring agents vary widely depending on the specific compounds used. Generally, these compounds are rapidly absorbed through the gastrointestinal tract upon ingestion, with their effects occurring within minutes. Some flavoring agents may undergo metabolism in the liver, while others may be excreted unchanged. The specific absorption, distribution, metabolism, and excretion (ADME) profiles depend on the chemical structure of each flavor compound.

Pregnancy

Generally considered safe, but specific flavoring agents may need to be evaluated individually.

Breast-feeding

Generally considered safe, but specific flavoring agents may need to be evaluated individually.

Storage

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

Indications

• Enhancement of taste in food and beverages
• Improvement of palatability in nutritional products
• Masking undesirable flavors in medications

Dosage

Children: There is no specific pediatric dosage for flavor agents as they are used as needed to improve the taste of food and beverages.

Adults: There is no specific dosage for flavor agents as they are used as needed to achieve the desired taste and aroma in food and beverages.

Mechanism of action

Flavor compounds interact with taste receptors on the tongue, stimulating the sensory neurons responsible for taste perception. This interaction influences the overall flavor profile of food and beverages, enhancing the eating experience. Some flavors may also have a psychological effect, stimulating appetite or evoking pleasant memories associated with certain tastes.

Pharmacodynamics

While flavor agents are primarily used for sensory enhancement in food, their pharmacodynamic effects are minimal as they are not designed to elicit a pharmacological response. However, certain flavors may influence digestion and metabolism indirectly by enhancing saliva production or affecting gut motility. The enjoyment of flavored products can also lead to increased food intake and satisfaction.

Pharmacokinetics

Flavour compounds are typically ingested and metabolized by the body. Their absorption rates can vary depending on their chemical structure and formulation. Once ingested, they may be rapidly metabolized in the liver and other tissues, with excretion primarily via urine. The specific pharmacokinetic profiles of flavor agents can vary significantly based on their source and chemical properties.

Pregnancy

Flavours are generally considered safe for use during pregnancy, but specific assessments should be made based on the type of flavouring agent.

Breast-feeding

Most flavouring agents are deemed safe during breastfeeding, although it's advisable to consult healthcare professionals regarding specific ingredients.

Storage

Store in a cool, dry place away from direct sunlight and heat sources. Ensure that the container is tightly sealed to prevent contamination.

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 guidelines for pediatric dosing; consult the BNF for Children for accurate dosage information.

Adults: Refer to specific guidelines for use; dosage may vary based on the context of use.

Mechanism of action

Hydroxide ions act primarily as bases, neutralizing acids to form water and salts. They participate in various biochemical pathways, including selenium metabolism and the degradation of reactive oxygen species. Hydroxide can influence enzyme activity and stability by altering the pH of the environment, thereby affecting metabolic reactions.

Pharmacodynamics

Hydroxide ions can impact biological processes by changing the local pH, which influences enzyme activity, ion transport, and the solubility of other compounds. Their ability to neutralize acids can help regulate physiological pH, contributing to homeostasis in living organisms.

Pharmacokinetics

As an inorganic ion, hydroxide does not undergo traditional pharmacokinetic processes like absorption, distribution, metabolism, or excretion. Instead, it is rapidly equilibrated in biological fluids and participates in acid-base reactions, having immediate effects on the local environment.

Pregnancy

There is limited information regarding the use of hydroxide during pregnancy. Consult a healthcare professional for advice.

Breast-feeding

Limited data is available on the excretion of hydroxide in breast milk. Consult a healthcare professional before use.

Storage

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

Indications

• Used as a low-calorie sweetener in food products
• Suitable for sugar-free candies and chewing gum
• Recommended for individuals with diabetes or those managing weight

Dosage

Children: Similar to adults, isomalt is used in food products aimed at children, but specific dosing should align with dietary recommendations. Refer to the BNF for Children for further guidance.

Adults: Isomalt is generally used in food products and does not have a specific therapeutic dosing regimen. Refer to food product guidelines for usage amounts.

Mechanism of action

Isomalt affects calcium absorption in the intestine by directly interacting with the epithelial tissue, promoting the net transport of calcium across the intestinal epithelium. Studies suggest that isomalt, alongside other sugar alcohols, can influence calcium uptake from both the small and large intestine in vitro, potentially impacting mineral balance due to its binding properties with calcium.

Pharmacodynamics

Isomalt's pharmacodynamic profile is characterized by its low glycemic index and minimal impact on insulin levels, making it suitable for diabetic patients. Its ability to act as a non-cariogenic sweetener contributes to oral health, and it may play a role in calcium metabolism, although further research is required to fully understand its effects on dental remineralization.

Pharmacokinetics

Isomalt is poorly absorbed in the gastrointestinal tract, leading to its classification as a low-calorie sweetener. The unabsorbed portion can ferment in the colon, potentially leading to gastrointestinal symptoms in some individuals. It does not significantly affect blood glucose levels, which makes it suitable for use by individuals with diabetes. Isomalt's metabolism primarily involves fermentation by colonic bacteria.

Pregnancy

Isomalt is generally considered safe for use during pregnancy as it is a non-cariogenic sweetener and is not known to have harmful effects on fetal development.

Breast-feeding

Isomalt is also considered safe during breastfeeding, as it is not absorbed significantly in the gastrointestinal tract and is unlikely to affect breast milk.

Storage

Isomalt should be stored in a cool, dry place, away from direct sunlight and moisture to maintain its quality.

Formulations

• Sugar-free candy
• Chewing gum

Dosage

Children: Paediatric fluid requirements should be calculated based on age, weight, and clinical condition. Refer to the guidelines in the BNF for Children for detailed recommendations.

Adults: Dosage in litres may vary depending on clinical circumstances, such as fluid resuscitation needs, maintenance fluid requirements, or medication delivery. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Litres do not have a pharmacological mechanism of action as they are a unit of measurement rather than a drug. However, the administration of fluids measured in litres can influence various physiological processes, including hydration status, electrolyte balance, and overall fluid homeostasis in the body.

Pharmacodynamics

As a measurement unit, litres do not exhibit pharmacodynamics. However, the volume of fluid administered can impact the pharmacodynamics of medications that are diluted or delivered in fluid form, affecting the rate of absorption, distribution, metabolism, and excretion of drugs.

Pharmacokinetics

Litres as a unit of volume do not possess pharmacokinetic properties. The pharmacokinetics of a drug may be influenced by the volume of fluid in which it is administered, as this can affect the concentration of the drug in the bloodstream and its subsequent pharmacological effects.

Indications

• Dental applications (e.g., dental cements, composites)
• Orthopedic applications (e.g., bone cements)
• Cosmetic uses (e.g., nail adhesives, fillers)

Dosage

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

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

Mechanism of action

Methacrylate compounds undergo polymerization, a chemical reaction where monomers (small molecules) link together to form a polymer chain. This process is typically initiated by heat, light, or chemical catalysts. The resulting polymers exhibit enhanced strength, flexibility, and adhesion, making them suitable for applications in dentistry, orthopedics, and aesthetics.

Pharmacodynamics

The pharmacodynamic properties of methacrylate compounds are primarily related to their ability to form stable polymer matrices. These polymers provide structural support and can release therapeutic agents when used in medical applications. The biocompatibility of methacrylate polymers is crucial, allowing them to integrate well with biological tissues without eliciting significant immune responses.

Pharmacokinetics

Methacrylate compounds are generally not absorbed systemically when used in dental or topical applications. Their pharmacokinetics are largely characterized by local retention at the site of application. The polymerization process limits the availability of free methacrylate monomers, reducing the likelihood of systemic effects. Metabolism and excretion pathways for methacrylate compounds are not extensively documented, as they primarily remain at the application site.

Pregnancy

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

Breast-feeding

Limited information is available regarding the excretion of methacrylate compounds in breast milk. Caution is recommended when using during lactation.

Storage

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

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.

Dosage

Children: Refer to BNF for Children for specific recommendations regarding the consumption of orange juice in children.

Adults: There is no standard dosage for orange juice as it is typically consumed as a beverage. Moderation is advised, especially for individuals on certain medications.

Mechanism of action

The exact mechanism of action of orange juice is not fully understood, but it is known to contain compounds that can influence the metabolism of certain drugs. For instance, it may affect the activity of cytochrome P450 enzymes, particularly CYP3A4, which can alter the pharmacokinetics of medications.

Pharmacodynamics

Orange juice is known to enhance the bioavailability of certain nutrients and may influence the pharmacological effects of some drugs. Its high vitamin C content contributes to various physiological functions, including antioxidant activity, which may indirectly support overall health.

Pharmacokinetics

The pharmacokinetics of orange juice itself are not extensively studied, but it is generally absorbed well through the gastrointestinal tract. The compounds in orange juice can affect the absorption and metabolism of medications, leading to varied clinical effects depending on the drug in question.

Interactions

• orange juice + celiprolol: Unknown (decreases exposure)

Formulations

• juice
• whole fruit

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

• 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

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

• Silicosis
• Chronic obstructive pulmonary disease (COPD)
• Lung cancer associated with silica exposure

Dosage

Adults: Silica is not administered as a drug, but rather

Mechanism of action

Silica, particularly crystalline forms like quartz and cristobalite, can induce cytotoxicity and morphological transformation in cells. The cytotoxic effects are attributed to the presence of silanol groups and trace iron on the silica surface, which can generate reactive oxygen species. These interactions lead to cellular damage and transformation, suggesting multiple molecular mechanisms underlying silica's biological effects. The activity is sensitive to the silica's surface structure and composition, indicating that the biological response is a phenomenon originating from the silica's surface characteristics.

Pharmacodynamics

Silica's pharmacodynamic effects are largely related to its cytotoxic and transforming properties, particularly in lung tissue. The inhalation of crystalline silica can lead to the activation of inflammatory pathways, oxidative stress, and apoptosis in alveolar macrophages and epithelial cells. This can result in chronic inflammation, fibrosis, and ultimately, diseases such as silicosis and lung cancer. The degree of these effects varies based on the type of silica, its crystalline structure, and the presence of surface modifications.

Pharmacokinetics

The pharmacokinetics of silica is complex as it is not absorbed systemically when inhaled or ingested. Instead, inhaled silica particles can deposit in the alveolar region of the lungs, where they may persist for long periods. The body responds to silica exposure through inflammatory processes, and macrophages attempt to phagocytize silica particles. However, the persistence of these particles can lead to chronic lung conditions. Clearance mechanisms are inefficient, leading to prolonged retention in lung tissue.

Adverse effects

• Cytotoxicity
• Morphological transformation of cells
• Respiratory issues
• Silicosis
• Lung cancer

Precautions

• Use caution in occupational settings with silica dust exposure
• Regular monitoring of lung function in exposed individuals

Pregnancy

There is insufficient data on the effects of silica on pregnancy. It is advised to minimize exposure.

Breast-feeding

Limited data available; caution is advised due to potential respiratory effects.

Storage

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

Formulations

• Crystalline silica
• Amorphous silica (diatomaceous earth)
• Silica gel

Indications

• Dry skin conditions
• Cosmetic formulations
• Emollient in topical creams and lotions
• Emulsifying agent in pharmaceutical preparations

Dosage

Children: For pediatric use, refer to specific product formulations and guidelines, as dosing may vary based on the formulation and concentration.

Adults: Stearyl alcohol is used topically in various formulations. Specific dosing is typically determined by the formulation and intended use, refer to product guidelines for detailed instructions.

Mechanism of action

Stearyl alcohol functions primarily as an emollient and emulsifier. It aids in the formation of stable emulsions by reducing the surface tension between oil and water phases, allowing for the creation of creams and lotions. Its hydrophobic tail interacts with lipids, while the hydroxyl group can form hydrogen bonds with water, enhancing moisture retention in the skin.

Pharmacodynamics

Stearyl alcohol acts by providing a protective barrier on the skin, reducing transepidermal water loss and enhancing hydration. Its emollient properties make it effective in softening and smoothing the skin, which can alleviate dryness and improve the overall appearance of the skin. Additionally, it can enhance the delivery of other active ingredients in topical formulations.

Pharmacokinetics

Stearyl alcohol is not significantly absorbed systemically when applied topically. Its primary action is local to the site of application, where it exerts its emollient effects. The compound is metabolized in the body to various fatty acids and alcohols, and it is excreted primarily through the skin and gastrointestinal tract, with minimal systemic exposure.

Pregnancy

Stearyl is generally considered safe for use during pregnancy; however, specific formulations should be evaluated for their ingredients.

Breast-feeding

Stearyl can be used while breastfeeding, but it's recommended to consult a healthcare provider for specific concerns regarding topical applications.

Storage

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

Formulations

• Cream
• Ointment
• Lotion

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.

Mechanism of action

Mannitol is an osmotic diuretic that is metabolically inert in humans and occurs naturally, as a sugar or sugar alcohol, in fruits and vegetables. Mannitol elevates blood plasma osmolality, resulting in enhanced flow of water from tissues, including the brain and cerebrospinal fluid, into interstitial fluid and plasma. As a result, cerebral edema, elevated intracranial pressure, and cerebrospinal fluid volume and pressure may be reduced. As a diurectic mannitol induces diuresis because it is not reabsorbed in the renal tubule, thereby increasing the osmolality of the glomerular filtrate, facilitating excretion of water, and inhibiting the renal tubular reabsorption of sodium, chloride, and other solutes. Mannitol promotes the urinary excretion of toxic materials and protects against nephrotoxicity by preventing the concentration of toxic substances in the tubular fluid. As an Antiglaucoma agent mannitol levates blood plasma osmolarity, resulting in enhanced flow of water from the eye into plasma and a consequent reduction in intraocular pressure. As a renal function diagnostic aid mannitol is freely filtered by the glomeruli with less than 10% tubular reabsorption. Therefore, its urinary excretion rate may serve as a measurement of glomerular filtration rate (GFR). The exact mechanism of action of inhaled mannitol in the symptomatic maintenance treatment of cystic fibrosis remains unclear. It is hypothesized that mannitol produces an osmotic gradient across the airway epithelium that draws fluid into the extracellular space and alters the properties of the airway surface mucus layer, allowing easier mucociliary clearance. MANNITOL IS.../USED/ IN PROPHYLAXIS OF ACUTE RENAL FAILURE. IT IS USED FOR THIS PURPOSE IN CONDITIONS AS DIVERSE AS CARDIOVASCULAR OPERATIONS, SEVERE TRAUMATIC INJURY, OPERATIONS IN THE PRESENCE OF SEVERE JAUNDICE, AND MGMNT OF HEMOLYTIC TRANSFUSION REACTIONS. IN EACH OF THESE CONDITIONS, A PRECIPITOUS FALL IN THE FLOW OF URINE MAY BE ANTICIPATED EITHER AS THE RESULT OF AN ACUTELY REDUCED FILTRATION RATE OR FROM ACUTE CHANGES IN TUBULAR PERMEABILITY. THE LATTER MAY BE CONSEQUENCE OF THE PRESENCE OF NOXIOUS AGENT WITHIN THE TUBULAR FLUID IN EXCESSIVELY HIGH CONCN, IN SOME INSTANCES SUFFICIENT TO RESULT IN ACTUAL PRECIPITATION. IN THESE SITUATIONS, MANNITOL EXERTS OSMOTIC EFFECT WITHIN THE TUBULAR FLUID, INHIBITS WATER REABSORPTION, & MAINTAINS THE RATE OF URINE FLOW. ...CONCN OF TOXIC AGENT WITHIN TUBULAR FLUID DOES NOT REACH EXCESSIVELY HIGH LEVELS THAT OTHERWISE WOULD HAVE BEEN ACHIEVED BY MORE COMPLETE REABSORPTION OF WATER. ...EVEN THOUGH /GLOMERULAR/ FILTRATION RATE IS REDUCED, MANNITOL IS STILL FILTERED @ GLOMERULUS. THE TUBULAR IMPERMEABILITY TO MANNITOL IS NOT ALTERED BY ACUTE RENAL ISCHEMIA OF SHORT DURATION. HENCE, THE MANNITOL THAT IS FILTERED IS ALSO EXCRETED IN THE VOIDED URINE. UNREABSORBED SOLUTE LIMITS BACK DIFFUSION OF WATER. ...URINE VOL CAN BE MAINTAINED EVEN IN PRESENCE OF DECR GLOMERULAR FILTRATION.

Pharmacodynamics

Chemically, mannitol is an alcohol and a sugar, or a polyol; it is similar to xylitol or sorbitol. However, mannitol has a tendency to lose a hydrogen ion in aqueous solutions, which causes the solution to become acidic. For this reason, it is not uncommon to add a substance to adjust its pH, such as sodium bicarbonate. Mannitol is commonly used to increase urine production (diuretic). It is also used to treat or prevent medical conditions that are caused by an increase in body fluids/water (e.g., cerebral edema, glaucoma, kidney failure). Mannitol is frequently given along with other diuretics (e.g., furosemide, chlorothiazide) and/or IV fluid replacement. Inhaled mannitol has the possibility to cause bronchospasm and hemoptysis; the occurrence of either should lead to discontinuation of inhaled mannitol.

Mechanism of action

Pyrimethamine inhibits the dihydrofolate reductase of plasmodia and thereby blocks the biosynthesis of purines and pyrimidines, which are essential for DNA synthesis and cell multiplication. This leads to failure of nuclear division at the time of schizont formation in erythrocytes and liver. Pyrimethamine is an antimalarial drug that has also been used successfully to treat autoimmune diseases such as lymphoproliferative syndrome. In this work, the effect of pyrimethamine (PYR) on the production of free radicals in malaria-infected mice was studied to better understand the drug's immunomodulatory properties. BALB/c and CBA/Ca mice were infected with Plasmodium yoelii 17XL. Seven days after infection, mice were treated with PYR or vehicle and sacrificed 24h later. Treatment with PYR increased superoxide dismutase and glutathione peroxidase activities in erythrocytes and the liver, augmented the levels of nitric oxide in the serum, and upregulated mRNA levels of superoxide dismutase, glutathione peroxidase, catalase, and iNOS in the spleen. In addition, PYR increased lipoperoxidation and protein carbonylation in infected mice. Our results indicate that P. yoelii 17XL reduces oxidative stress in infected cells, while PYR induces it, which is associated with increased parasite elimination. Thus, it is possible that oxidative stress generated by pyrimethamine is also involved in its immunomodulatory mechanism of action. Co-infection of human immunodeficiency virus (HIV) with malaria is one of the pandemic problems in Africa and parts of Asia. Here we investigated the impact of pyrimethamine (PYR) and two other clinical anti-malarial drugs (chloroquine [CQ] or artemisinin [ART]) on HIV-1 replication. Peripheral blood mononuclear cells (PBMCs) or MT-2 cells were infected with HIV(NL4.3) strain and treated with different concentrations of the anti-malarial drugs. HIV-1 replication was measured using p24 ELISA. We show that 10 uM CQ and ART inhibited HIV-1 replication by 76% and 60% in PBMCs, respectively, but not in MT-2 cells. In contrast, 10 uM PYR enhanced HIV-1 replication in MT-2 cells by >10-fold. A series of molecular mechanism studies revealed that PYR increased intracellular HIV gag proteins without affecting the promoter or the reverse transcriptase activity. The effect of PYR was independent of HTLV-1 produced by MT-2 cells. Of interest, PYR treatment led to S-phase accumulation and increased AZT and d4T antiviral activity by ~ 4-fold. Taken together, we show that PYR significantly enhances HIV-1 replication by affecting the cellular machinery. Our results could be relevant for the management of malaria and HIV particularly in regions where HIV-1 and malaria epidemics overlap. Autosomal dominant polycystic kidney disease (ADPKD) is a commonly inherited disorder mostly caused by mutations in PKD1, encoding polycystin-1 (PC1). The disease is characterized by development and growth of epithelium-lined cyst in both kidneys, often leading to renal failure. There is no specific treatment for this disease. Here, we report a sustained activation of the transcription factor signal transducer and activator of transcription 3 (STAT3) in ischemic injured and uninjured Pkd1 knockout polycystic kidneys and in human ADPKD kidneys. Through a chemical library screen, we identified the anti-parasitic compound pyrimethamine as an inhibitor of STAT3 function. Treatment with pyrimethamine decreases cell proliferation in human ADPKD cells and blocks renal cyst formation in an adult and a neonatal PKD mouse model. Moreover, we demonstrated that a specific STAT3 inhibitor, S3I-201, reduces cyst formation and growth in a neonatal PKD mouse model. Our results suggest that PC1 acts as a negative regulator of STAT3 and that blocking STAT3 signaling with pyrimethamine or similar drugs may be an attractive therapy for human ADPKD. The unresponsiveness of metastatic melanoma to conventional chemotherapeutic and biological agents is largely due to the de

Pharmacodynamics

Pyrimethamine is an antiparasitic compound commonly used as an adjunct in the treatment of uncomplicated, chloroquine resistant, P. falciparum malaria. Pyrimethamine is a folic acid antagonist and the rationale for its therapeutic action is based on the differential requirement between host and parasite for nucleic acid precursors involved in growth. This activity is highly selective against plasmodia and Toxoplasma gondii. Pyrimethamine possesses blood schizonticidal and some tissue schizonticidal activity against malaria parasites of humans. However, the 4-amino-quinoline compounds are more effective against the erythrocytic schizonts. It does not destroy gametocytes, but arrests sporogony in the mosquito. The action of pyrimethamine against Toxoplasma gondii is greatly enhanced when used in conjunction with sulfonamides.

Mechanism of action

The mechanism of plasmodicidal action of amodiaquine is not completely certain. Like other quinoline derivatives, it is thought to inhibit heme polymerase activity. This results in accumulation of free heme, which is toxic to the parasites. The drug binds the free heme preventing the parasite from converting it to a form less toxic. This drug-heme complex is toxic and disrupts membrane function. Amodiaquine is a Mannich base 4-aminoquinoline with a mode of action similar to that of chloroquine. It is effective against some chloroquine-resistant strains of P. falciparum, although there is cross-resistance. The 4-aminoquinoline derivatives appear to bind to nucleoproteins and interfere with protein synthesis in susceptible organisms; the drugs intercalate readily into double-stranded DNA and inhibit both DNA and RNA polymerase. In addition, the drugs apparently concentrate in parasite digestive vacuoles, increase the pH of the vacuoles, and interfere with the parasite's ability to metabolize and utilize erythrocyte hemoglobin. Plasmodial forms that do not have digestive vacuoles and do not utilize hemoglobin, such as exoerythrocytic forms, are not affected by /these medications/. The 4-aminoquinoline derivatives ... have anti-inflammatory activity; however, the mechanism(s) of action of the drugs in the treatment of rheumatoid arthritis and lupus erythematosus has not been determined. /4-aminoquinoline derivatives/ reportedly antagonizes histamine in vitro, has antiserotonin effects, and inhibits prostaglandin effects in mammalian cells presumably by inhibiting conversion of arachidonic acid to prostaglandin F2. The mode of action of amodiaquine has not yet been determined. 4-Aminoquinolines depress cardiac muscle, impair cardiac conductivity, and produce vasodilatation with resultant hypotension; they depress respiration and cause diplopia, dizziness and nausea.

Pharmacodynamics

Amodiaquine, a 4-aminoquinoline similar to chloroquine in structure and activity, has been used as both an antimalarial and an anti-inflammatory agent for more than 40 years. Amodiaquine is at least as effective as chloroquine, and is effective against some chloroquine-resistant strains, although resistance to amodiaquine has been reported. The mode of action of amodiaquine has not yet been determined. 4-Aminoquinolines depress cardiac muscle, impair cardiac conductivity, and produce vasodilatation with resultant hypotension. They depress respiration and cause diplopia, dizziness and nausea.

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

/Investigators/ compared the effect of a variety of sugar alcohols on calcium absorption from the rat small and large intestine in vitro. An Using chamber technique was used to determine the net transport of Ca across the epithelium isolated from the jejunum, ileum, cecum, and colon of rats. The concentration of Ca in the serosal and mucosal Tris buffer solution was 1.25 mM and 10 mM, respectively. The Ca concentration in the serosal medium was determined after incubation for 30 min and the net Ca absorption was evaluated. The addition of 0.1-200 mM erythritol, xylitol, sorbitol, maltitol, palatinit, or lactitol to the mucosal medium affected net Ca absorption in the intestinal preparations. Differences in Ca transport were observed between portions of the intestine, but not between sugar alcohols tested. /The authors/ concluded that sugar alcohols directly affect the epithelial tissue and promote Ca absorption from the small and large intestine in vitro. Isomalt is a non-cariogenic sweetener, which is widely used in sugar-free candy and chewing gum. Little is known about the effects of Isomalt on de- and remineralization. Binding between calcium and Isomalt has been reported, which could affect the mineral balance. The objective of this study was to examine the effects of Isomalt on de- and remineralization of bovine enamel lesions, both in vitro and in situ. In in vitro study, subsurface enamel lesions were subjected to 3-weeks pH-cycling. Treatments were 5-min rinses with 10% Isomalt solutions daily and 10% Isomalt additions to re- or demineralizing solutions. Standard pH-cycling conditions were used with a 0.2 ppm fluoride background during the remineralization phase. In in situ study, subsurface lesions were exposed 2 months in vivo and brushed three times daily with 10% Isomalt containing toothpaste. Treatment effects were assessed by chemical analysis of the solutions (in vitro) and transversal microradiography (in vitro and in situ). In in vitro study, while 5-min rinses with 10% Isomalt gave slightly increased remineralization, continuous presence of 10% Isomalt (in re- or demineralizing solutions) inhibited both de- and/or remineralization. This lead to significantly smaller overall mineral loss when Isomalt was added during demineralization. In in situ study, remineralization enhancement during short Isomalt treatments was confirmed. Isomalt had a positive effect on the de/remineralization balance when given under conditions relevant to practical use. ... Reports from authoritative bodies and reviews indicates that the decrease in pH in plaque as a consequence of metabolic acid production by saccharolytic bacteria when exposed to fermentable carbohydrates (i.e. sugars and starches) may promote demineralization and prevent remineralization of the hydroxyapatite crystals. Tooth hydroxyapatite crystals are very resistant to dissolution at neutral pH, but their solubility drastically increases as pH drops. Typically, the critical pH for dental enamel is around 5.5. ... Demineralization of tooth tissues can also occur as a result of consumption of dietary acids in foods or beverages, and that frequent consumption can lead to dental erosion. Xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt, erythritol, D-tagatose, isomaltulose, sucralose and polydextrose are slowly metabolized by bacteria in the mouth. The rate and amount of acid production from these food constituents is significantly less than that from sucrose. ... Xylitol, sorbitol, mannitol, maltitol, lactitol, isomalt, erythritol, D-tagatose, isomaltulose, sucralose and polydextrose do not promote dental caries because they do not lower plaque pH to the level associated with enamel demineralization. ... A cause and effect relationship has been established between the consumption of sugar-containing foods/drinks at an exposure frequency of four times daily or more and an increased tooth demineralization, and that the consumption of foods/drinks containing xyl

Mechanism of action

...Some quartz and cristobalite dusts (crystalline) as well as the diatomaceous earths (amorphous), but not the pyrogenic amorphous silica, were cytotoxic and induced morphological transformation of SHE cells in a concentration-dependent manner. The ranking in cytotoxicity was different from that in transforming potency, suggesting two separate molecular mechanisms for the two effects. The cytotoxic and transforming potencies were different from one dust to another, even among the same structural silicas. The type of crystalline structure (quartz vs cristobalite) and the crystalline vs biogenic amorphous form did not correlate with cytotoxic or transforming potency of silica dusts. Comparison of cellular effects induced by original and surface modified samples revealed that several surface functionalities modulate cytotoxic and transforming potencies. The cytotoxic effects appeared to be related to the distribution and abundance of silanol groups and to the presence of trace amounts of iron on the silica surface. Silica particles with fractured surfaces and/or iron-active sites, able to generate reactive oxygen species, induced SHE cell transformation. The results show that the activity of silica at the cellular level is sensitive to the composition and structure of surface functionalities and confirm that the biological response to silica is a surface originated phenomenon. In vivo exposure of rat lungs to crystalline silica either by intratracheal instillation or by inhalation results in an increase in mRNA levels for inducible nitric oxide synthase (iNOS) in bronchoalveolar lavage cells (BALC), elevated nitric oxide (.NO) production by BALC, and an increase in .NO-dependent chemiluminescence (CL) from alveolar macrophages (AM). Induction of iNOS message occurs in both AM and polymorphonuclear leukocytes (PMN) harvested from silica-exposed lungs but is not significantly elevated in lavaged lung tissue. This review presents characteristics of simple and complicated coal workers' pneumoconiosis (CWP) as well as pathologic indices of acute and chronic silicosis by summarizing results of in vitro, animal, and human investigations. These results support four basic mechanisms in the etiology of CWP and silicosis: a) direct cytotoxicity of coal dust or silica, resulting in lung cell damage, release of lipases and proteases, and eventual lung scarring; b) activation of oxidant production by pulmonary phagocytes, which overwhelms the antioxidant defenses and leads to lipid peroxidation, protein nitrosation, cell injury, and lung scarring; c) activation of mediator release from alveolar macrophages and epithelial cells, which leads to recruitment of polymorphonuclear leukocytes and macrophages, resulting in the production of proinflammatory cytokines and reactive species and in further lung injury and scarring; d) secretion of growth factors from alveolar macrophages and epithelial cells, stimulating fibroblast proliferation and eventual scarring. Results of in vitro and animal studies provide a basis for proposing these mechanisms for the initiation and progression of pneumoconiosis. Data obtained from exposed workers lend support to these mechanisms. /The authors/ reported previously that freshly fractured silica (FFSi) induces activator protein-1 (AP-1) activation through extracellular signal-regulated protein kinases (ERKs) and p38 kinase pathways. In the present study, the biologic activities of FFSi and aged silica (ASi) were compared by measuring their effects on the AP-1 activation and phosphorylation of ERKs and p38 kinase. The roles of reactive oxygen species (ROS) in this silica-induced AP-1 activation were also investigated. FFSi-induced AP-1 activation was four times higher than that of ASi in JB6 cells. FFSi also caused greater phosphorylation of ERKs and p38 kinase than ASi. FFSi generated more ROS than ASi when incubated with the cells as measured by electron spin resonance (ESR). Studies using ROS-sensitive dyes and

Mechanism of action

It has very good absorptive properties.