NICOZONE ORAL SUSPENSION

Indications

• Helminth infections
• Strongyloidiasis
• Hydatid disease
• Tapeworm infections
• Hookworm infections
• Schistosomiasis

Dosage

Children: For children aged 2–17 years: 400 mg twice daily for 3 days. The dose may be repeated after 3 weeks if necessary. Alternatively, for hookworm infections: 7.5 mg/kg twice daily (maximum per dose 400 mg) for 28 days, followed by a 14-day break, repeated for up to 2–3 cycles.

Adults: For Adult patients, the dosage is typically 400 mg taken by mouth as a single dose or as directed by a healthcare professional based on the specific condition being treated.

Mechanism of action

Albendazole works by inhibiting the polymerization of tubulin into microtubules, disrupting the cytoplasmic structure of the helminths, and thereby inhibiting their motility and reproduction.

Pharmacodynamics

Albendazole exhibits its anthelmintic activity through the inhibition of glucose uptake, leading to depletion of glycogen stores in the worms, ultimately resulting in their death. It is effective against a wide range of parasites.

Pharmacokinetics

Albendazole is rapidly absorbed and is metabolized in the liver to its primary active metabolite, albendazole sulfoxide. Its bioavailability is increased when taken with fatty meals. The drug is primarily excreted in the urine and has a half-life that varies based on individual metabolism.

Adverse effects

• Gastro-intestinal upset
• Lightheadedness
• Pruritus

Interactions

• Levamisole may moderately decrease the exposure to albendazole
• Ritonavir may decrease the exposure to albendazole

Precautions

• Treatment must be given under careful patient supervision
• Stop at the first sign of cerebral involvement

Pregnancy

Refer to BNF for specific guidance.

Breast-feeding

Refer to BNF for specific guidance.

Storage

Store in a cool, dry place away from light.

Formulations

• Tablets
• Suspension

Indications

• Dry eye syndrome
• Ocular surface disorders
• Topical lubrication
• Pharmaceutical excipients in formulations

Dosage

Children: Refer to specific product guidelines, as doses may vary by formulation and indication.

Adults: Refer to specific product guidelines, as doses may vary by formulation and indication.

Mechanism of action

Carboxymethyl cellulose acts by forming a viscous gel when it comes into contact with water. This gel-like consistency helps to retain moisture, providing lubrication and protection to ocular surfaces. The polymer's ability to bind water makes it effective at enhancing the viscosity of formulations, which can prolong the retention time of active ingredients in contact with the affected tissues.

Pharmacodynamics

Carboxymethyl cellulose exhibits its effects primarily through its physical properties rather than specific biochemical interactions. Its high viscosity contributes to a protective barrier on mucosal surfaces, aiding in the alleviation of dryness and irritation. The gel-forming property helps to maintain hydration and can facilitate the healing process of epithelial tissues.

Pharmacokinetics

Carboxymethyl cellulose is not significantly absorbed through the gastrointestinal tract or ocular surfaces. Its action is mainly local, with minimal systemic absorption. The polymer is excreted unchanged, and its viscosity and gel-forming capabilities are maintained until it is cleared from the application site through natural processes such as blinking or swallowing.

Adverse effects

• Allergic reactions
• Skin irritation
• Gastrointestinal disturbances
• Headache
• Dizziness

Precautions

• Use with caution in patients with known allergies to carboxymethyl derivatives
• Monitor for potential allergic reactions
• Consider potential interactions with other medications

Pregnancy

Safety during pregnancy has not been established. Use only if potential benefits justify the risks.

Breast-feeding

It is not known whether carboxymethyl is excreted in human milk. Caution should be exercised.

Storage

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

Formulations

• Carboxymethyl cellulose sodium (CMC) - commonly used as a thickening agent in various formulations

Indications

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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Powder
• Capsules
• Tablets
• Granules

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

• Dry skin
• Skin irritation
• Eczema
• Dermatitis
• Cosmetic applications as a moisturizer and thickening agent

Dosage

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

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

Mechanism of action

Dimethicone works by forming a protective layer on the skin, which helps to seal in moisture and protect the skin from irritants. Its anti-foaming properties are due to its ability to reduce surface tension, allowing gas bubbles to coalesce and escape more easily, thus diminishing the formation of foam in solutions.

Pharmacodynamics

Dimethicone exhibits emollient properties, which means it can soften and soothe the skin. It acts by creating a barrier that prevents transepidermal water loss, thereby enhancing hydration. Its non-irritating nature makes it suitable for sensitive skin, and it does not clog pores, making it a preferred choice in many dermatological preparations.

Pharmacokinetics

Dimethicone is not absorbed systemically; it remains on the skin surface and does not penetrate into the deeper layers of the skin. This characteristic makes it effective as a topical agent. Because it is not metabolized or excreted by the body, its pharmacokinetic profile is primarily focused on its local effects rather than systemic absorption.

Adverse effects

• Allergic reactions
• Skin irritation
• Gastrointestinal discomfort

Precautions

• Use with caution in patients with a history of allergic reactions to silicone-based compounds
• Monitor for any signs of adverse reactions during treatment

Pregnancy

Dimethicone is generally considered safe for use during pregnancy, as it is not absorbed systemically.

Breast-feeding

Dimethicone is considered safe for use during breastfeeding, as it is not absorbed and is unlikely to affect breastfed infants.

Storage

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

Formulations

• Topical creams
• Lotions
• Ointments
• Oral suspensions

Indications

• Nutritional support in patients unable to consume food orally
• Parenteral nutrition
• Drug delivery for lipophilic medications
• Topical applications for skin conditions

Dosage

Children: Refer to specific product guidelines and clinical protocols for paediatric dosing.

Adults: Refer to specific product guidelines and clinical protocols for adult dosing.

Mechanism of action

Emulsions work by reducing the surface tension between the oil and water phases, allowing for the formation of stable droplets. This process is mediated by emulsifying agents, which can be surfactants or natural polymers that stabilize the emulsion and prevent phase separation. The absorption and bioavailability of drugs within the emulsion can be enhanced due to the increased surface area for absorption.

Pharmacodynamics

The pharmacodynamics of emulsions vary based on their composition and formulation. The presence of emulsifying agents can influence the release profile of the active ingredients, allowing for controlled or sustained release. Emulsions can also enhance the solubility of poorly water-soluble drugs, improving their therapeutic effects and minimizing side effects related to high concentrations of active ingredients.

Pharmacokinetics

The pharmacokinetics of emulsions depend on their route of administration and the specific properties of the drug contained within the emulsion. After administration, emulsions can be rapidly absorbed due to their small droplet size, leading to quicker onset of action. The distribution, metabolism, and excretion of the drug will follow the pharmacokinetic principles applicable to the active ingredients, influenced by their solubility and the emulsion's formulation.

Pregnancy

The safety of emulsions during pregnancy depends on the specific type and formulation. Consult relevant guidelines and specific product information.

Breast-feeding

Emulsions may be used while breastfeeding, but specific product information should be consulted to ensure safety.

Storage

Store at room temperature, away from light and moisture. Specific formulations may have unique storage requirements.

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

Indications

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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

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

Interactions

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

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Tablets
• Injectable solutions
• Topical preparations

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Pregnancy

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

Breast-feeding

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

Storage

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

Indications

• Cestodiasis
• Tapeworm infections
• Taeniasis
• Hymenolepiasis
• Enterobiasis (Oxyuriasis)

Dosage

Children: For children, dosages should be determined based on specific recommendations from the BNF for Children, taking into account the child's age and weight.

Adults: The typical adult dosage of niclosamide is 2 grams taken as a single oral dose, after fasting for at least 2 hours. It is important to consult the BNF for specific recommendations.

Mechanism of action

Niclosamide exerts its action by uncoupling oxidative phosphorylation in the mitochondria of the tapeworms, inhibiting energy production and leading to the accumulation of lactic acid, which ultimately kills the parasites. It also inhibits glucose absorption by the tapeworm, further contributing to its cestocidal activity. Additionally, it may damage the DNA of the parasites, enhancing its efficacy.

Pharmacodynamics

As an antihelminth, niclosamide disrupts the metabolic processes of cestodes. By uncoupling the electron transport chain from ATP synthase, niclosamide prevents the synthesis of ATP, a critical energy source for the parasites. This results in impaired energy metabolism and contributes to the death of the worms.

Pharmacokinetics

Niclosamide is poorly absorbed from the gastrointestinal tract, which is beneficial for its intended use as it acts locally within the intestine. Following administration, the drug is largely excreted unchanged in the feces. Due to its limited systemic absorption, systemic side effects are uncommon.

Adverse effects

• Nausea
• Vomiting
• Abdominal pain
• Diarrhea
• Headache
• Dizziness

Precautions

• Use with caution in patients with liver impairment
• Monitor for gastrointestinal effects

Pregnancy

Niclosamide should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether niclosamide is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Tablets

Indications

• Preservative in cosmetics
• Preservative in pharmaceuticals
• Preservative in food products

Dosage

Children: Refer to specific product guidelines as dosing varies based on formulation and concentration used.

Adults: Refer to specific product guidelines as dosing varies based on formulation and concentration used.

Mechanism of action

Parabens work by inhibiting the growth of microorganisms through their ability to disrupt the cellular processes of bacteria and fungi. They penetrate the microbial cell membrane and disrupt enzyme and protein functions, leading to cell death. Parabens are known to have low toxicity and are metabolized by the body, subsequently being excreted in urine.

Pharmacodynamics

Parabens demonstrate broad-spectrum antimicrobial activity, making them effective preservatives in various formulations. Their efficacy is influenced by factors such as concentration, pH, and the presence of other ingredients in the formulation. Due to their structural similarity to estrogen, there has been concern regarding their potential endocrine-disrupting effects, although the clinical significance of this is still debated.

Pharmacokinetics

Parabens are readily absorbed through the skin and gastrointestinal tract. Once absorbed, they are rapidly metabolized primarily in the liver. They undergo hydrolysis to form para-hydroxybenzoic acid, which is then conjugated with glucuronic acid and excreted in urine. The half-life of parabens in the human body is relatively short, and they are eliminated rapidly.

Adverse effects

• Allergic reactions, such as skin rashes
• Irritation at the site of application
• Endocrine disruption (in high concentrations)

Precautions

• Use with caution in individuals with known sensitivities or allergies to parabens
• Consider potential endocrine effects with prolonged exposure

Pregnancy

Parabens are generally considered safe in cosmetics and personal care products during pregnancy, although caution is advised due to potential endocrine disruption.

Breast-feeding

Parabens are considered safe in breastfeeding, but it is recommended to use products with minimal or no parabens when possible.

Storage

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

Formulations

• Topical creams
• Lotions
• Shampoos
• Conditioners
• Makeup products
• Pharmaceutical preparations

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

• Used as a solvent for oral, injectable, and topical medications
• Involved in the formulation of certain anesthetics
• Used in cosmetic and personal care products

Dosage

Children: Refer to specific product labeling for dosing information, as it varies depending on the formulation and intended use.

Adults: Refer to specific product labeling for dosing information, as it varies depending on the formulation and intended use.

Mechanism of action

Propylene glycol acts primarily as a solvent and carrier for drugs, facilitating their absorption and bioavailability. It enhances the solubility of hydrophobic drugs in aqueous solutions, which aids in the formulation of injectable and oral dosage forms. Additionally, it may also have mild antimicrobial properties, contributing to the preservation of formulations.

Pharmacodynamics

As a low toxicity solvent, propylene glycol does not exert significant pharmacological effects on its own. However, its role in drug formulation can influence the pharmacodynamics of the active pharmaceutical ingredients (APIs) it carries. The effectiveness of the drug can be enhanced due to improved solubility and absorption, ultimately affecting the drug's therapeutic effects.

Pharmacokinetics

Propylene glycol is readily absorbed from the gastrointestinal tract and distributed throughout the body. It is metabolized primarily in the liver via the enzyme alcohol dehydrogenase to lactic acid and pyruvate, which are then utilized in energy metabolism. The elimination half-life of propylene glycol is relatively short, and it is excreted mainly through urine as non-toxic metabolites. Its pharmacokinetic profile may vary based on the route of administration and the presence of other drugs.

Pregnancy

Propylene is generally considered safe during pregnancy as it is not known to cause harm to the developing fetus, but caution should be exercised and it should only be used if clearly needed.

Breast-feeding

Propylene is typically regarded as safe during breastfeeding, but it is advisable to consult a healthcare provider before use.

Storage

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

Indications

• Hyperthyroidism
• Graves' disease
• Thyroid storm

Dosage

Children: Refer to the BNF

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Interactions

• propylthiouracil+metyrapone: Severe (decreases effects)

Indications

• Thickening agent in food products
• Stabilizer in pharmaceutical formulations
• Emulsifier in cosmetic products
• Dietary fiber supplement

Dosage

Children: Dosage should be determined based on specific formulations and medical advice. Refer to the BNF for Children for detailed guidance.

Adults: Dosage depends on the specific formulation and purpose. Refer to product-specific guidelines or consult the BNF.

Mechanism of action

Xanthan gum works by forming a viscous gel in the presence of water. This gelling property is due to its unique molecular structure, which consists of a repeating unit of glucose, mannose, and glucuronic acid. When hydrated, xanthan gum can create a three-dimensional network that traps water, thus increasing the viscosity of the solution. This ability to enhance the texture and stability of various formulations is what makes xanthan gum a valuable ingredient in many products.

Pharmacodynamics

The pharmacodynamic properties of xanthan gum are primarily related to its thickening and stabilizing effects. It does not possess any pharmacological activity in the traditional sense, as it is not absorbed into the systemic circulation. Instead, its primary function is to modify the rheological properties of the formulations it is included in, affecting how they flow and interact with other ingredients.

Pharmacokinetics

Xanthan gum is not metabolized by the body and is considered safe for consumption. It is largely excreted unchanged in the feces. The gastrointestinal absorption of xanthan gum is minimal, which means it does not exert systemic effects. Upon ingestion, it may contribute to dietary fiber intake, promoting digestive health. Its viscosity can also influence gastrointestinal transit time, potentially providing a feeling of fullness.

Adverse effects

• Gastrointestinal discomfort
• Flatulence
• Diarrhea
• Bloating
• Allergic reactions (rare)

Precautions

• Use with caution in individuals with gastrointestinal disorders
• Monitor for allergic reactions in sensitive individuals

Pregnancy

Xanthan gum is generally considered safe for use during pregnancy as it is a food additive and not absorbed in significant amounts.

Breast-feeding

Xanthan gum is considered safe during breastfeeding as it is not absorbed systemically.

Storage

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

Formulations

• Powder
• Gel
• Liquid
• Capsules

Mechanism of action

Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by diminishing its energy production, ultimately leading to immobilization and death of the parasite. It works by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. As cytoplasmic microtubules are critical in promoting glucose uptake in larval and adult stages of the susceptible parasites, the glycogen stores of the parasites are depleted. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Benzimidazoles produce many biochemical changes in susceptible nematodes, eg, inhibition of mitochondrial fumarate reductase, reduced glucose transport, and uncoupling of oxidative phosphorylation ... /but/ the primary action ... /should be/ to inhibit microtubule polymerization by binding to beta-tubulin. The selective toxicity of these agents derives from the fact that specific, high-affinity binding to parasite beta-tubulin occurs at much lower concn than does binding to the mammalian protein ... Benzimidazole-resistant Haemonchus contortus display reduced high-affinity drug binding to beta-tubulin and alterations in beta-tubulin isotype gene expression that correlate with drug resistance ... Two identified mechanisms of drug resistance in nematodes involve both a progressive loss of "susceptible" beta-tubulin gene isotypes together with emergence of a "resistant" isotype with a conserved point mutation that encodes a tyrosine instead of phenylalanine at position 200 of beta-tubulin. While this mutation may not be required for benzimidazole resistance in all parasites, eg, Giardia lamblia, benzimidazole resistance in parasitic nematodes is unlikely to be overcome by novel benzimidazole analogs, because tyrosine also is present at position 200 of human beta-tubulin. /Benzimidazoles/ Although the exact mechanism of action of albendazole has not been fully elucidated, the principal anthelmintic effect of benzimidazoles, including albendazole, appears to be the specific, high-affinity binding of the drug to free beta-tubulin in parasite cells, resulting in selective inhibition of parasite microtubule polymerization, and inhibition of microtubule-dependent uptake of glucose. Benzimidazole drugs bind to the beta-tubulin of parasites at much lower concentrations than to mammalian beta-tubulin protein; the drugs do not inhibit glucose uptake in mammals, and do not appear to have any effect on blood glucose concentrations in humans The mode of action of albendazole is by binding strongly with the tubulin in the cells of nematodes. The intestinal cells of the nematode are particularly affected, resulting in a loss of absorptive function which causes the nematodes to starve to death.

Pharmacodynamics

Albendazole is a broad-spectrum anthelmintic. The principal mode of action for albendazole is by its inhibitory effect on tubulin polymerization which results in the loss of cytoplasmic microtubules.

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

Niclosamide works by killing tapeworms on contact. Adult worms (but not ova) are rapidly killed, presumably due to uncoupling of oxidative phosphorylation or stimulation of ATPase activity. The killed worms are then passed in the stool or sometimes destroyed in the intestine. Niclosamide may work as a molluscicide by binding to and damaging DNA. Niclosamide has prominent activity against most of the cestodes that infect man; Enterobius (Oxyuris) vermicularis is also susceptible. At low concn, niclosamide stimulates oxygen uptake by Hymenolepis diminuta, but at higher concn respiration is inhibited and glucose uptake is blocked. The principal action of the drug may be to inhibit anaerobic phosphorylation of adenosine diphosphate (ADP) by the mitochondria of the parasite, an energy producing process that is dependent on CO2 fixation ... . Cestocidal activity is due to inhibition of absorption of glucose by the tapeworm and uncoupling of the oxidative phosphorylation process in the mitochondria of cestodes. Resultant blocking of the Krebs cycle leads to accumulation of lactic acid, which kills the tapeworm. ... overstimulation of adenosine triphosphatase (ATPase) activity of the mitochondria may be related to cestodal action of niclosamide.

Pharmacodynamics

Niclosamide is an antihelminth used against tapeworm infections. It may act by the uncoupling of the electron transport chain to ATP synthase. The disturbance of this crucial metabolic pathway prevents creation of adenosine tri-phosphate (ATP), an essential molecule that supplies energy for metabolism.