CLOPIDREL

Indications

• Prevention of atherothrombotic events in patients with acute coronary syndrome
• Secondary prevention of ischaemic stroke
• Prevention of atherothrombotic events in peripheral arterial disease

Mechanism of action

Clopidogrel is activated through a two-step metabolic process to form an active thiol-containing metabolite. This metabolite irreversibly binds to the P2Y12 ADP receptors on platelets, preventing ADP from activating the GPIIb/IIIa complex, which is crucial for platelet aggregation. As a result, clopidogrel inhibits platelet aggregation for the lifespan of the platelets (approximately 7 to 10 days). The inhibition of the P2Y12 receptor reduces platelet activation and aggregation not just from ADP, but also from other agonists.

Pharmacodynamics

Clopidogrel is a prodrug that serves as a potent antiplatelet agent, effectively reducing the risk of myocardial infarction and stroke. Its pharmacological effects are long-lasting, allowing for once-daily dosing. Clopidogrel exhibits a broad therapeutic window, and its dosage ranges from 75 mg to 300 mg per day, depending on the clinical scenario. Its action helps maintain blood flow and prevent occlusive vascular events.

Pharmacokinetics

Clopidogrel is well absorbed in the gastrointestinal tract, with peak plasma concentrations occurring within 1 to 2 hours after oral administration. It undergoes extensive hepatic metabolism, primarily through CYP450 enzymes, which convert it into its active form. The elimination half-life of clopidogrel is approximately 6 hours, but the antiplatelet effect lasts much longer due to the irreversible nature of its action on platelets. It is primarily excreted through urine, with a majority of the dose eliminated as inactive metabolites.

Contra-indications

• Active bleeding

Adverse effects

• Confusion
• Fever
• Gynaecomastia
• Hallucination
• Hepatic disorders
• Hypotension
• Myalgia
• Neutropenia
• Severe cutaneous adverse reactions (SCARs)
• Stomatitis
• Taste altered
• Ulcerative colitis
• Vasculitis
• Vertigo
• Wound haemorrhage

Interactions

• Voriconazole + clopidogrel: Severe (decreases efficacy)
• HIV protease inhibitors + clopidogrel: Severe (decreases efficacy)
• Moclobemide + clopidogrel: Severe (decreases efficacy)
• Ritonavir + clopidogrel: Severe (decreases efficacy)
• Clopidogrel + pioglitazone: Moderate (increases exposure)
• Clopidogrel + treprostinil: Moderate (increases exposure)
• Clopidogrel + apalutamide: Unknown (increases exposure)
• Clopidogrel + enzalutamide: Unknown (increases exposure)
• Fluconazole + clopidogrel: Unknown (decreases efficacy)
• Clopidogrel + anti-androgens: Unknown (increases exposure)

Precautions

• Caution with history of hypersensitivity reactions to thienopyridines
• Caution in moderate hepatic impairment
• Caution in renal impairment
• Discontinue 7 days before elective surgery if antiplatelet effect not desirable
• Patients at risk of increased bleeding from trauma, surgery, or other pathological conditions

Pregnancy

Manufacturer advises avoid-no information available.

Breast-feeding

Manufacturer advises avoid.

Storage

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

Formulations

• Clopidogrel 75 mg tablet
• Clopidogrel 300 mg tablet
• Clopidogrel oral suspension

Indications

• Food preservation
• Antioxidant applications
• Reduction of oxidative stress

Dosage

Children: Refer to specific guidelines or consult a healthcare professional for dosing recommendations, as doses can vary based on the indication.

Adults: Refer to specific guidelines or consult a healthcare professional for dosing recommendations, as doses can vary based on the indication.

Mechanism of action

Bisulphate acts as a reducing agent, donating electrons to other molecules, which can help in neutralizing free radicals and preventing oxidative stress. It interacts with sulfite oxidase in the body, facilitating the conversion of sulfite to sulfate, a less toxic form. This mechanism is particularly relevant in the context of sulfite metabolism and detoxification.

Pharmacodynamics

Bisulphate's pharmacodynamics are primarily related to its antioxidant properties. It helps to protect cells from oxidative damage by scavenging free radicals. The compound also plays a role in maintaining the acid-base balance in the body, as it can act as a buffer in certain physiological conditions.

Pharmacokinetics

Bisulphate is rapidly absorbed and metabolized in the body. It is primarily metabolized in the liver, where it is converted to sulfate. The elimination route is mainly through urine, where it is excreted as sulfate. The half-life of bisulphate is short, necessitating frequent dosing in certain applications.

Adverse effects

• Headache
• Nausea
• Diarrhea
• Skin rash
• Hypersensitivity reactions

Precautions

• Use with caution in patients with asthma or respiratory issues
• Monitor for allergic reactions in sensitive individuals

Pregnancy

The safety of bisulphate during pregnancy has not been established. Use only if clearly needed and after assessing risks versus benefits.

Breast-feeding

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

Storage

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

Indications

• Constipation
• Labor induction
• Topical treatment for skin conditions

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting
• Dehydration

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Liquid
• Capsules

Indications

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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

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

Pregnancy

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

Breast-feeding

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

Storage

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

Formulations

• Powder
• Capsules
• Tablets
• Granules

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Pregnancy

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

Breast-feeding

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

Storage

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

Indications

• Used as an excipient in pharmaceutical formulations
• Improves solubility and stability of active ingredients
• Facilitates drug absorption

Dosage

Children: Refer to specific product guidelines as hydroxypropyl is typically used as an excipient and not dosed independently.

Adults: Refer to specific product guidelines as hydroxypropyl is typically used as an excipient and not dosed independently.

Mechanism of action

Hydroxypropyl functions primarily as a solubilizing agent, which aids in the dissolution of poorly soluble drugs. It interacts with water and other solvents to improve the dispersion of pharmaceutical compounds, thereby enhancing their bioavailability. Hydroxypropyl may also facilitate the permeability of drug molecules through biological membranes, contributing to their overall efficacy.

Pharmacodynamics

The pharmacodynamics of hydroxypropyl relate to its role in improving the physicochemical properties of drug formulations. By increasing solubility and stability, hydroxypropyl can enhance the absorption of drugs administered via various routes, including oral and topical. Its non-toxic nature allows for safe incorporation into formulations, making it suitable for a wide range of applications.

Pharmacokinetics

The pharmacokinetics of hydroxypropyl have not been extensively studied as it primarily acts as an excipient rather than an active pharmaceutical ingredient. When used in formulations, it is typically not absorbed into systemic circulation in significant amounts, thereby minimizing potential systemic effects. Hydroxypropyl is generally regarded as safe when used in appropriate amounts in drug formulations.

Pregnancy

Hydroxypropyl is not classified for use during pregnancy, and its safety has not been established. Caution is advised.

Breast-feeding

There is limited information on the excretion of hydroxypropyl in human milk. Caution is advised when administering to breastfeeding women.

Storage

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

Indications

• Skin irritation
• Minor cuts
• Abrasions
• Superficial skin lesions

Dosage

Children: Apply a thin layer to the affected area as needed, following the manufacturer's instructions.

Adults: Apply a thin layer to the affected area as needed, following the manufacturer's instructions.

Mechanism of action

The specific mechanism of action of Instacoat can vary depending on its active ingredients. Generally, topical formulations exhibit local effects by forming a protective layer over the skin, which can help in preventing infection and facilitating the natural healing process. Some ingredients may have anti-inflammatory properties that reduce redness and swelling, while others may promote cellular regeneration and wound healing.

Pharmacodynamics

Instacoat acts locally at the site of application, with minimal systemic absorption. The pharmacodynamic effects are mainly related to the ingredients used in the formulation. These effects can include enhancement of skin hydration, reduction of inflammation, and promotion of tissue regeneration. The overall outcome is improved skin integrity and faster healing of affected areas.

Pharmacokinetics

As a topical agent, Instacoat is primarily applied to the skin, resulting in localized effects. The pharmacokinetics would largely depend on the specific formulation and its active components. Typically, topical medications show limited systemic absorption, ensuring that the primary effects are exerted locally. The onset of action may occur within a few hours following application, with the duration of effect varying based on the formulation and skin characteristics.

Pregnancy

Data on the use of Instacoat during pregnancy is limited. Its use should be considered only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

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

Storage

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

Indications

• Acute poisoning
• Drug overdose
• Gastrointestinal disturbances
• Diarrhea
• Flatulence

Dosage

Children: Refer to specific product guidelines or consult a healthcare provider for appropriate dosage.

Adults: Refer to specific product guidelines or consult a healthcare provider for appropriate dosage.

Mechanism of action

Microcelac works primarily through physical adsorption. Activated charcoal has a high surface area which allows it to bind various substances, including drugs and toxins, in the gastrointestinal tract. This binding prevents their absorption into the systemic circulation, thereby facilitating their elimination through feces.

Pharmacodynamics

The pharmacodynamic profile of Microcelac is characterized by its ability to bind to various organic compounds and inorganic substances, reducing their bioavailability and effects. The extent of adsorption can vary based on the nature of the substance, the dose of activated charcoal, and the time elapsed since ingestion. It does not chemically alter the substances adsorbed, but effectively reduces their absorption and systemic effects.

Pharmacokinetics

Microcelac is not absorbed through the gastrointestinal tract; instead, it remains within the gut lumen where it exerts its effects by adsorbing toxins. The elimination of the drug occurs through feces, as the bound toxins and the unabsorbed drug are excreted following gastrointestinal transit.

Pregnancy

Safety during pregnancy has not been established; consult a healthcare provider before use.

Breast-feeding

Limited data available; a healthcare provider should be consulted before use while breastfeeding.

Storage

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

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Pregnancy

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

Breast-feeding

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

Storage

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

Dosage

Children: Refer to BNF for Children for appropriate dosing guidelines for paediatric patients.

Adults: Refer to specific guidelines or BNF for the appropriate dosing of substituted drugs as they vary widely based on the specific compound and its clinical use.

Mechanism of action

The mechanism of action for substituted drugs typically involves interaction with specific biological targets such as receptors, enzymes, or ion channels. By binding to these targets, substituted drugs can modulate various physiological processes, leading to desired therapeutic effects, such as analgesia, anti-inflammatory action, or modulation of neurotransmitter activity.

Pharmacodynamics

Pharmacodynamics of substituted drugs depends on their specific structure and target interactions. Generally, they exert effects through receptor activation or inhibition, leading to alterations in signaling pathways. This can result in enhanced or diminished cellular responses, contributing to the overall therapeutic outcome. The potency and efficacy of these drugs can vary widely based on their chemical modifications.

Pharmacokinetics

The pharmacokinetics of substituted drugs involves absorption, distribution, metabolism, and excretion (ADME). Factors such as the lipophilicity, molecular weight, and chemical stability of the substituents can affect how the drug is absorbed in the gastrointestinal tract, distributed throughout the body, metabolized by the liver, and ultimately excreted through the kidneys. Variations in these parameters will influence the drug's bioavailability, half-life, and duration of action.

Pregnancy

Consult healthcare provider before use. Safety during pregnancy has not been established.

Breast-feeding

Consult healthcare provider before use. Limited data available on safety during breastfeeding.

Storage

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

Mechanism of action

Clopidogrel is activated via a 2 steps reaction to an active thiol-containing metabolite. This active form is a platelet inhibitor that irreversibly binds to P2Y₁₂ ADP receptors on platelets. This binding prevents ADP binding to P2Y₁₂ receptors, activation of the glycoprotein GPIIb/IIIa complex, and platelet aggregation. Clopidogrel must be metabolized by CYP450 enzymes to produce the active metabolite that inhibits platelet aggregation. The active metabolite of clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet P2Y12 receptor and the subsequent ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation. This action is irreversible. Consequently, platelets exposed to clopidogrel's active metabolite are affected for the remainder of their lifespan (about 7 to 10 days). Platelet aggregation induced by agonists other than ADP is also inhibited by blocking the amplification of platelet activation by released ADP. The P2Y12 receptor plays a crucial role in the regulation of platelet activation by several agonists, which is irreversibly antagonized by the active metabolite of clopidogrel, a widely used anti-thrombotic drug. In this study, we investigated whether reduction of platelet reactivity leads to reduced inflammatory responses using a rat model of erosive arthritis. We evaluated the effect of clopidogrel on inflammation in Lewis rats in a peptidoglycan polysaccharide (PG-PS)-induced arthritis model with four groups of rats: 1) untreated, 2) clopidogrel-treated, 3) PG-PS-induced, and 4) PG-PS-induced and clopidogrel-treated. There were significant differences between the PG-PS+clopidogrel group when compared to the PG-PS group including: increased joint diameter and clinical manifestations of inflammation, elevated plasma levels of pro-inflammatory cytokines (IL-1 beta, interferon (IFN) gamma, and IL-6), an elevated neutrophil blood count and an increased circulating platelet count. Plasma levels of IL-10 were significantly lower in the PG-PS+clopidogrel group compared to the PG-PS group. Plasma levels of platelet factor 4 (PF4) were elevated in both the PG-PS and the PG-PS+clopidogrel groups, however PF4 levels showed no difference upon clopidogrel treatment, suggesting that the pro- inflammatory effect of clopidogrel may be due to its action on cells other than platelets. Histology indicated an increase in leukocyte infiltration at the inflammatory area of the joint, increased pannus formation, blood vessel proliferation, subsynovial fibrosis and cartilage erosion upon treatment with clopidogrel in PG-PS-induced arthritis animals. In summary, animals treated with clopidogrel showed a pro-inflammatory effect in the PG-PS-induced arthritis animal model, which might not be mediated by platelets.

Pharmacodynamics

Clopidogrel is a prodrug of a platelet inhibitor used to reduce the risk of myocardial infarction and stroke. It has a long duration of action as it is taken once daily and a large therapeutic window as it is given in doses of 75-300mg daily.