AFATEK 40

Indications

• Non-small cell lung cancer (NSCLC) with EGFR mutations
• Locally advanced or metastatic NSCLC after progression on prior chemotherapy
• First-line treatment for metastatic NSCLC with common EGFR mutations

Dosage

Children: Safety and efficacy in paediatric patients have not been established; refer to the BNF for Children for specific dosing recommendations.

Adults: The recommended starting dose of Afatinib for adults is 40 mg once daily, which may be increased to 50 mg once daily based on tolerability and clinical response.

Mechanism of action

Afatinib irreversibly binds to the tyrosine kinase domain of the EGFR family, inhibiting phosphorylation and subsequent activation of the receptor. This leads to a downstream blockade of signaling pathways involved in cell growth, proliferation, and survival, particularly the MAPK and PI3K-AKT pathways, resulting in reduced tumor growth.

Pharmacodynamics

The pharmacodynamic effects of Afatinib manifest as reduced tumor cell proliferation and enhanced apoptosis in cancer cells that express activating mutations of EGFR. The drug has been shown to improve progression-free survival in patients with EGFR mutation-positive NSCLC compared to standard chemotherapy. Common side effects include diarrhea, rash, and stomatitis, which are indicative of its mechanism of action on epithelial tissues.

Pharmacokinetics

Afatinib is well absorbed following oral administration, with peak plasma concentrations occurring approximately 2 to 5 hours post-dose. Its bioavailability is approximately 100%, and it has a mean elimination half-life of about 37 hours. Afatinib is extensively metabolized in the liver, predominantly by CYP3A4 and UGT1A1 pathways, with excretion occurring primarily through feces. Due to its long half-life, it is typically administered once daily.

Adverse effects

• diarrhoea
• dizziness
• haemorrhage
• headache
• increased liver enzymes
• skin reactions

Interactions

• calcium channel blockers (increases exposure)
• ciclosporin (increases exposure)
• ivacaftor (increases exposure)
• lapatinib (increases exposure)
• macrolides (increases exposure)
• neratinib (increases exposure)
• ranolazine (increases exposure)
• rucaparib (increases exposure)
• St. John's wort (decreases exposure)
• tacrolimus (increases exposure)

Precautions

• Caution in patients with cardiac risk factors
• Monitor cardiac ejection fraction at baseline and during treatment
• Consider alternative treatment options in patients at high risk for thromboembolic disease
• Protect skin from sun exposure due to risk of skin cancer
• Monitor for signs and symptoms of infection, especially in patients at increased risk

Pregnancy

Avoid use during pregnancy due to potential risk to the fetus; seek advice regarding reproductive health.

Breast-feeding

Avoid breastfeeding during treatment and for 2 days after the last dose, as it may be present in breast milk.

Storage

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

Formulations

• Afatinib 40 mg oral tablet
• Afatinib 30 mg oral tablet
• Afatinib 20 mg oral tablet
• Afatinib 50 mg oral tablet

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

• 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

• 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

• Osteoarthritis
• Rheumatoid arthritis
• Acute pain
• Chronic pain
• Musculoskeletal disorders
• Post-operative pain
• Migraine

Dosage

Children: Refer to age-specific dosing guidelines and consult the BNF for Children for appropriate dosing based on weight and age.

Adults: Refer to clinical guidelines and specific product information as doses may vary based on formulation and indication.

Mechanism of action

Dimaleate works primarily as a non-steroidal anti-inflammatory drug (NSAID), exerting its effects by inhibiting the cyclooxygenase (COX) enzymes which are crucial in the biosynthesis of prostaglandins. Prostaglandins are lipid compounds that mediate inflammation, pain, and fever. By reducing their production, dimaleate alleviates pain and inflammation in affected tissues.

Pharmacodynamics

The pharmacodynamic effects of dimaleate include its anti-inflammatory, analgesic, and antipyretic actions. These effects are due to the inhibition of COX enzymes, leading to a decrease in the formation of pro-inflammatory prostaglandins. The onset of action typically occurs within a few hours after administration, providing symptomatic relief for a range of inflammatory conditions.

Pharmacokinetics

Dimaleate is absorbed relatively quickly from the gastrointestinal tract, with peak plasma concentrations usually achieved within a few hours of oral administration. It is metabolized primarily in the liver, with metabolites excreted mainly through the kidneys. The half-life of the drug may vary depending on the formulation and individual patient factors, but it generally allows for dosing intervals that provide sustained therapeutic effects.

Pregnancy

Safety 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 this drug is excreted in human milk. Caution should be exercised when administering to breastfeeding women.

Storage

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

Indications

• Monitoring respiratory function
• Assessment of metabolic status
• Management of respiratory acidosis
• Management of respiratory alkalosis

Dosage

Children: Dosing for interventions related to carbon dioxide levels in pediatric patients should be guided by clinical protocols and the BNF for Children.

Adults: Dosing for interventions related to carbon dioxide levels is typically based on clinical assessment and individual patient needs. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Carbon dioxide acts primarily as a signaling molecule in the body, influencing respiratory drive and blood pH. It is produced during cellular respiration and is a critical component of the bicarbonate buffering system, which helps maintain acid-base homeostasis. Elevated levels of CO2 in the blood stimulate ventilation in the lungs, increasing the rate of gas exchange and facilitating the removal of excess CO2.

Pharmacodynamics

The pharmacodynamic effects of dioxides, particularly carbon dioxide, are closely related to its concentration in the blood. As CO2 levels increase, it leads to respiratory acidosis, which can stimulate the respiratory centers in the brain to increase ventilation. Conversely, low levels of CO2 can cause respiratory alkalosis, potentially leading to decreased respiratory drive. CO2 also plays a role in vasodilation and can affect blood flow and pressure through its influence on smooth muscle tone.

Pharmacokinetics

Carbon dioxide is produced endogenously during metabolic processes and is transported in the bloodstream primarily in three forms: dissolved in plasma, as bicarbonate ions (HCO3-), and bound to hemoglobin. The half-life of CO2 in the bloodstream is very short due to its rapid exchange with alveolar gas in the lungs. The elimination of CO2 occurs through exhalation, making it a dynamic component of respiratory physiology.

Pregnancy

Data on the effects of dioxide during pregnancy are limited. Caution is advised due to potential risks associated with exposure.

Breast-feeding

Limited data are available regarding the excretion of dioxide in human milk. Caution is recommended.

Storage

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

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

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

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

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.

Indications

• Potential role in bone health
• Support for connective tissue formation
• May aid in mineral metabolism

Dosage

Children: There is no established clinical dosage for silicon in paediatric populations, as it is not classified as an essential nutrient.

Adults: There is no established clinical dosage for silicon in adults, as it is not classified as an essential nutrient.

Mechanism of action

Silicon is believed to enhance the synthesis of glycosaminoglycans and collagen, which are important for the structural integrity of connective tissues. It may also influence the activity of certain enzymes involved in bone mineralization, thus playing a role in maintaining bone density and health.

Pharmacodynamics

The pharmacodynamics of silicon is not fully elucidated; however, it is thought to involve the modulation of bone metabolism and the promotion of connective tissue health. Silicon may have a synergistic effect with other minerals, such as calcium and magnesium, aiding in their utilization and metabolism in the body.

Pharmacokinetics

The pharmacokinetics of silicon is complex, as it is not absorbed through typical gastrointestinal pathways. Instead, silicon is thought to be taken up in the form of silicates and then distributed throughout the body, particularly in connective tissues. The elimination of silicon occurs primarily through renal excretion, with some variations depending on dietary intake and individual metabolism.

Pregnancy

Silicon is generally considered safe during pregnancy, as it is a naturally occurring element in the human body. However, specific recommendations regarding supplementation should be followed based on the advice of a healthcare provider.

Breast-feeding

Silicon is present in breast milk in small amounts. Its safety during breastfeeding is generally regarded as acceptable, although supplementation should be approached with caution and under medical advice.

Storage

Silicon should be stored in a cool, dry place, protected from light and moisture. Follow specific storage recommendations provided by the manufacturer if available.

Dosage

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

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

Mechanism of action

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

Pharmacodynamics

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

Pharmacokinetics

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

Mechanism of action

Afatinib is a potent and selective, irreversible ErbB family blocker. Afatinib covalently binds to and irreversibly blocks signaling from all homo and heterodimers formed by the ErbB family members EGFR (ErbB1), HER2 (ErbB2), ErbB3 and ErbB4. In particular, afatinib covalently binds to the kinase domains of EGFR (ErbB1), HER2 (ErbB2), and HER4 (ErbB4) and irreversibly inhibits tyrosine kinase autophosphorylation, resulting in downregulation of ErbB signaling. Certain mutations in EGFR, including non-resistant mutations in its kinase domain, can result in increased autophosphorylation of the receptor, leading to receptor activation, sometimes in the absence of ligand binding, and can support cell proliferation in NSCLC. Non-resistant mutations are defined as those occurring in exons constituting the kinase domain of EGFR that lead to increased receptor activation and where efficacy is predicted by 1) clinically meaningful tumor shrinkage with the recommended dose of afatinib and/or 2) inhibition of cellular proliferation or EGFR tyrosine kinase phosphorylation at concentrations of afatinib sustainable at the recommended dosage according to validated methods. The most commonly found of these mutations are exon 21 L858R substitutions and exon 19 deletions. Moreover, afatinib demonstrated inhibition of autophosphorylation and/or in vitro proliferation of cell lines expressing wild-type EGFR and in those expressing selected EGFR exon 19 deletion mutations, exon 21 L858R mutations, or other less common non-resistant mutations, at afatinib concentrations achieved in patients. In addition, afatinib inhibited in vitro proliferation of cell lines overexpressing HER2.

Pharmacodynamics

Aberrant ErbB signaling triggered by receptor mutations, and/or amplification, and/or receptor ligand overexpression contributes to the malignant phenotype. Mutation in EGFR defines a distinct molecular subtype of lung cancer. In non-clinical disease models with ErbB pathway deregulation, afatinib as a single agent effectively blocks ErbB receptor signaling resulting in tumor growth inhibition or tumor regression. NSCLC tumors with common activating EGFR mutations (Del 19, L858R) and several less common EGFR mutations in exon 18 (G719X) and exon 21 (L861Q) are particularly sensitive to afatinib treatment in non-clinical and clinical settings. Limited non-clinical and/or clinical activity was observed in NSCLC tumors with insertion mutations in exon 20. The acquisition of a secondary T790M mutation is a major mechanism of acquired resistance to afatinib and gene dosage of the T790M-containing allele correlates with the degree of resistance in vitro. The T790M mutation is found in approximately 50% of patients' tumors upon disease progression on afatinib, for which T790M targeted EGFR TKIs may be considered as a next line treatment option. Other potential mechanisms of resistance to afatinib have been suggested preclinically and MET gene amplification has been observed clinically. At the same time, the effect of multiple doses of afatinib (50 mg once daily) on cardiac electrophysiology and the QTc interval was evaluated in an open-label, single-arm study in patients with relapsed or refractory solid tumors. Ultimately, no large changes in the mean QTc interval (i.e., >20 ms) were detected in the study.