REBLESS-20

Indications

• Prophylaxis of venous thromboembolism following knee replacement surgery
• Prophylaxis of venous thromboembolism following hip replacement surgery
• Treatment of deep vein thrombosis
• Treatment of pulmonary embolism

Dosage

Adults: For the prophylaxis of venous thromboembolism following knee replacement surgery: 10 mg once daily for 2 weeks, starting 6–10 hours

Mechanism of action

Rivaroxaban competitively inhibits both free and clot-bound factor Xa. Factor Xa is essential for the conversion of prothrombin to thrombin, which is necessary for fibrinogen to be activated into fibrin, leading to clot formation. By inhibiting factor Xa, rivaroxaban effectively terminates the amplification of thrombin generation, preventing thrombus formation. Its action is irreversible and does not require a cofactor, distinguishing it from other anticoagulants like heparin.

Pharmacodynamics

Rivaroxaban exhibits anticoagulant properties by directly binding to factor Xa. This binding prevents the activation of prothrombin, thereby blocking the coagulation cascade and thrombus formation. Unlike traditional anticoagulants, rivaroxaban does not utilize antithrombin III to exert its effects, and it is administered orally, making it more convenient compared to parenteral anticoagulants.

Pharmacokinetics

Rivaroxaban is rapidly absorbed and reaches peak plasma concentrations within 2-4 hours after oral administration. It is extensively metabolized in the liver, primarily by CYP3A4 and CYP2J2, and is also a substrate for P-glycoprotein. The half-life of rivaroxaban is approximately 5-9 hours in healthy individuals, and it is excreted via both renal and fecal routes, with about 66% excreted as metabolites and 28% as unchanged drug.

Contra-indications

• Active bleeding
• Bacterial endocarditis
• Active gastrointestinal ulcer

Adverse effects

• Anaemia
• Haemorrhage
• Chest pain
• Dyspnoea
• Fever
• Hepatic function abnormality
• Nausea
• Oedema
• Platelet abnormalities
• Thrombocytopenia
• Vomiting
• Wound secretion
• Anxiety
• Confusion
• Constipation
• Cough
• Diarrhoea
• Dizziness
• Drowsiness
• Fatigue
• Gastritis
• Gastrointestinal discomfort
• Genital oedema
• Headache
• Hyperbilirubinaemia
• Hypersensitivity
• Hypokalaemia
• Hypotension
• Leg pain
• Post procedural infection
• Syncope
• Vasodilation
• Vertigo

Interactions

• tucatinib+rivaroxaban: Moderate (increases exposure)
• vemurafenib+rivaroxaban: Moderate (increases exposure)
• antiarrhythmics+rivaroxaban: Unknown (increases exposure)
• antiepileptics (carbamazepine, phenobarbital, phenytoin, primidone)+rivaroxaban: Unknown (decreases exposure)
• ciclosporin+rivaroxaban: Unknown (increases exposure)
• mitotane+rivaroxaban: Unknown (decreases exposure)
• NNRTIs+rivaroxaban: Unknown (decreases exposure)
• St. John's Wort+rivaroxaban: Unknown (decreases exposure)

Precautions

• Elderly patients
• Low body weight
• Spinal or epidural anaesthesia (risk of spinal haematoma)
• Patients with a history of bleeding disorders
• Patients undergoing percutaneous coronary intervention
• Patients with renal impairment

Pregnancy

Manufacturer advises to avoid unless potential benefit outweighs possible risk-no information available.

Breast-feeding

Present in milk in animal

Dosage

Children: Refer to specific product information for dosing guidelines.

Adults: Refer to specific product information for dosing guidelines.

Pregnancy

Consult healthcare provider for specific information regarding use during pregnancy.

Breast-feeding

Consult healthcare provider for specific information regarding use during breastfeeding.

Storage

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

Indications

• Used as a disintegrant in tablet formulations
• Enhances the bioavailability of active pharmaceutical ingredients

Dosage

Children: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Adults: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Mechanism of action

Croscarmellose sodium works by swelling and absorbing water when it comes into contact with gastrointestinal fluids. This swelling leads to the rapid disintegration of the tablet or capsule matrix, facilitating the release and absorption of the active pharmaceutical ingredients.

Pharmacodynamics

Croscarmellose sodium is classified as a superdisintegrant. Its ability to rapidly disintegrate solid dosage forms can significantly enhance the dissolution rate of the active ingredient, which is crucial for achieving therapeutic effects in a timely manner.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract and does not exert pharmacological effects in the body. It is considered non-toxic and is excreted unchanged. Its main role is as an excipient, influencing the formulation's characteristics rather than the pharmacokinetics of the active ingredients.

Precautions

• Use with caution in patients with known hypersensitivity to croscarmellose or its components.

Pregnancy

Safety in pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Caution is advised when using during breastfeeding, as safety has not been established.

Storage

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

Formulations

• Powder
• Granules

Indications

• Lactose intolerance
• As a filler or excipient in pharmaceutical formulations

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and clinical context.

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

Mechanism of action

Lactose is metabolized in the intestine by the enzyme lactase into its constituent monosaccharides, glucose and galactose. In individuals with lactase deficiency, unabsorbed lactose passes into the colon, where it is fermented by bacteria, leading to gas production and osmotic effects that contribute to diarrhea.

Pharmacodynamics

The pharmacodynamics of lactose are primarily related to its effects on gastrointestinal function. In healthy individuals, lactose is effectively broken down into glucose and galactose, which are absorbed and utilized for energy. In individuals with lactose intolerance, the unabsorbed lactose can cause osmotic diarrhea and colonic fermentation, leading to discomfort and symptoms associated with lactose intolerance.

Pharmacokinetics

Lactose is not absorbed in the gastrointestinal tract until it is hydrolyzed into glucose and galactose by lactase. The absorption of glucose and galactose occurs in the small intestine. The half-life is not applicable as lactose is not typically administered as a medication but is rather ingested as a natural component of food. Its metabolism primarily occurs in the intestine.

Adverse effects

• Bloating
• Diarrhea
• Abdominal pain
• Flatulence

Precautions

• Use with caution in patients with lactose intolerance.
• Consider potential for gastrointestinal upset in sensitive individuals.

Pregnancy

Lactose is generally considered safe for use during pregnancy. However, consult a healthcare professional for individual advice.

Breast-feeding

Lactose is safe to use while breastfeeding, as it is a natural sugar present in breast milk.

Storage

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

Formulations

• Powder
• Granules
• Tablets
• Syrup

Indications

• Cleansing agent in topical formulations
• Emulsifying agent in cosmetic products
• Foaming agent in shampoos and body washes

Dosage

Children: Refer to specific product formulations for appropriate concentrations and application methods.

Adults: Refer to specific product formulations for appropriate concentrations and application methods.

Mechanism of action

Lauryl sulfate functions as an anionic surfactant. It reduces the surface tension between different substances, allowing for better spreading and wetting. In the context of cleansing, it facilitates the removal of dirt and oils from the skin and hair by emulsifying these substances, thus making them easier to rinse away with water.

Pharmacodynamics

As a surfactant, lauryl sulfate displays properties that can disrupt cellular membranes and alter permeability. This mechanism is beneficial in enhancing the penetration of other therapeutic agents in topical formulations. However, its irritant potential on skin and mucous membranes should be noted, as it can lead to dryness and irritation with prolonged exposure.

Pharmacokinetics

Lauryl sulfate is primarily applied topically and is not intended for systemic absorption. When used in formulations, it acts locally at the site of application. Its absorption through the skin is minimal, and any systemic exposure is limited. Metabolism and excretion pathways are not well-defined for topical applications, as it is largely washed away after use.

Pregnancy

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

Breast-feeding

Unknown whether lauryl 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.

Indications

• Tablet coating
• Granule coating
• Improvement of drug stability
• Taste masking
• Aesthetic enhancement of pharmaceuticals

Dosage

Children: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Adults: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Mechanism of action

Opadry functions primarily as a coating polymer that adheres to the surface of tablets or granules, creating a protective layer. This layer can control the release of the active ingredient and protect it from environmental factors such as moisture and light. The specific composition of Opadry can vary, but it typically includes film-forming agents, plasticizers, and colorants that work together to achieve the desired coating characteristics.

Pharmacodynamics

The pharmacodynamics of Opadry is largely focused on its physical and chemical properties rather than specific biological interactions. The coating alters the dissolution characteristics of the drug, potentially leading to modified release profiles. This can enhance drug bioavailability or control the release rate of the active ingredient, thereby impacting the therapeutic effect.

Pharmacokinetics

As a coating agent, Opadry itself is not absorbed into the systemic circulation and does not have pharmacokinetic properties related to absorption, distribution, metabolism, or excretion of an active pharmaceutical ingredient. Its impact on pharmacokinetics is indirect, as it affects how the active drug is released and absorbed in the gastrointestinal tract.

Pregnancy

Opadry is a film-coating agent, and specific studies on its effects during pregnancy are not well-documented. Generally, it is advisable to use medications cautiously during pregnancy. Consult a healthcare provider for guidance.

Breast-feeding

Limited data are available regarding the safety of Opadry during breastfeeding. It is recommended to consult a healthcare provider before use.

Storage

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

Formulations

• Opadry OY - a coating system for oral solid dosage forms
• Opadry II - a polymer-based coating system for tablet and capsule applications

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.

Mechanism of action

Rivaroxaban competitively inhibits free and clot bound factor Xa. Factor Xa is needed to activate prothrombin (factor II) to thrombin (factor IIa). Thrombin is a serine protease that is required to activate fibrinogen to fibrin, which is the loose meshwork that completes the clotting process. Since one molecule of factor Xa can generate more than 1000 molecules of thrombin, selective inhibitors of factor Xa are profoundly useful in terminating the amplification of thrombin generation. The action of rivaroxaban is irreversible. Rivaroxaban, an oral, direct activated factor X (Xa) inhibitor, is an anticoagulant. Factor Xa plays a central role in the blood coagulation cascade by serving as the convergence point for the intrinsic and extrinsic pathways; inhibition of coagulation factor Xa by rivaroxaban prevents conversion of prothrombin to thrombin and subsequent thrombus formation. Rivaroxaban inhibits both free and prothrombinase-bound factor Xa. Unlike fondaparinux, heparin, and the low molecular weight heparins, rivaroxaban binds directly to the active site of factor Xa without the need for a cofactor (e.g., antithrombin III). Rivaroxaban inhibits factor Xa with more than 100,000-fold greater selectivity than other biologically important serine proteases (e.g., thrombin, trypsin, plasmin, factor VIIa, factor IXa, urokinase, activated protein C). Xarelto is an orally bioavailable factor Xa inhibitor that selectively blocks the active site of factor Xa and does not require a cofactor (such as Anti-thrombin III) for activity. Activation of factor X to factor Xa (FXa) via the intrinsic and extrinsic pathways plays a central role in the cascade of blood coagulation.

Pharmacodynamics

Rivaroxaban is an anticoagulant which binds directly to factor Xa. Thereafter, it effectively blocks the amplification of the coagulation cascade, preventing the formation of thrombus. Rivaroxaban is a unqiue anticoagulant for two reasons. First of all, it is does not involve antithrombin III (ATIII) to exert its anticoagulant effects. Secondly, it is an oral agent whereas the widely used unfractionated heparin and low molecular weight heparins are for parenteral use only. Although the activated partial thromboplastin time (aPTT) and HepTest (a test developed to assay low molecular weight heparins) are prolonged in a dose-dependant manner, neither test is recommended for the assessment of the pharmacodynamic effects of rivaroxaban. Anti-Xa activity and inhibition of anti-Xa activity monitoring is also not recommended despite being influenced by rivaroxaban.