ELYCLOB-G

Indications

• Vaginal candidiasis
• Vulval candidiasis
• Superficial fungal infections
• Otitis externa (as part of combination therapy)

Dosage

Adults: For vaginal candidiasis, 1 pessary of 500 mg can be inserted at night. Alternatively, for treatment with 1% cream, apply 2–3 times a day to the affected area for at least 14 days. For recurrent vulvovaginal candidiasis

Mechanism of action

Clotrimazole acts primarily by damaging the permeability barrier in the cell membrane of fungi. It inhibits ergosterol biosynthesis, which is essential for maintaining the integrity of fungal cell membranes. The inhibition of lanosterol 14-demethylase (CYP51) is a key mechanism behind its antifungal properties, leading to decreased ergosterol synthesis and resulting in cell membrane dysfunction. Clotrimazole also affects calcium homeostasis by inhibiting sarcoplasmic reticulum Ca2+-ATPase and blocking calcium-dependent potassium channels, contributing to its overall pharmacological effects.

Pharmacodynamics

Clotrimazole is considered a broad-spectrum antifungal that alters the permeability of fungal cell membranes, leading to inhibition of growth in pathogenic yeasts. At lower concentrations, it exhibits fungistatic properties, while at higher concentrations, it may be fungicidal against certain strains like Candida albicans. However, resistance to clotrimazole has become more common in recent years, limiting its efficacy in some populations.

Pharmacokinetics

Clotrimazole is primarily applied topically, and its absorption varies depending on the formulation and site of application. Following topical administration, systemic absorption is minimal, thereby reducing the risk of systemic side effects. The drug is metabolized in the liver and excreted via urine and feces. The pharmacokinetics may differ based on the dosing regimen and specific formulation used.

Contra-indications

• Hypersensitivity to clotrimazole or any excipients in the formulation
• Not recommended if trying to conceive due to potential damage to latex condoms and diaphragms

Adverse effects

• Skin reactions
• Vaginal burning
• Angioedema

Interactions

• Clotrimazole may increase the exposure of lomitapide, though the specific nature of this interaction is unknown

Precautions

• Avoid use in pregnancy without medical advice
• Use caution in patients with a history of hypersensitivity reactions

Pregnancy

Clotrimazole should be used during pregnancy only if clearly needed. Oral antifungal treatments should be avoided.

Breast-feeding

Clotrimazole is excreted in breast milk; caution is advised when used in breastfeeding mothers.

Storage

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

Formulations

• Clotrimazole 1% cream
• Clotrimazole 2% cream
• Clotrimazole 500 mg vaginal pessaries
• Clotrimazole 10% vaginal cream
• Clotrimazole 1% solution (ear drops)

Indications

• Prophylaxis of asthma
• Management of allergic rhinitis
• Treatment of nasal polyps

Dosage

Children: For children aged 2–11 years, the dose is 100–200 micrograms twice daily; for children aged 12–17 years, 200–400 micrograms twice daily, adjusted according to response.

Adults: For adults and children over 12 years with chronic asthma, the usual starting dose is 200-400 micrograms twice daily, which may be increased if necessary.

Mechanism of action

Beclometasone dipropionate acts by binding to glucocorticoid receptors in target cells, leading to the modulation of gene expression and the inhibition of pro-inflammatory cytokines, thereby reducing inflammation and hyperresponsiveness in the airways.

Pharmacodynamics

As a potent anti-inflammatory agent, beclometasone dipropionate decreases the infiltration of inflammatory cells into the airways, reduces mucus production, and enhances beta-adrenergic responsiveness. This results in improved airflow and reduced asthma symptoms.

Pharmacokinetics

Beclometasone dipropionate is administered via inhalation, where it undergoes extensive first-pass metabolism in the liver. Its systemic bioavailability is low due to significant hepatic metabolism. The drug has a long duration of action, with effects lasting for 12-24 hours, allowing for once or twice-daily dosing.

Contra-indications

• Hypersensitivity to beclometasone dipropionate or any of its excipients
• Hypersensitivity to atropine or its derivatives

Adverse effects

• Throat irritation
• Wheezing
• Nasal complaints
• Headache
• Nausea
• Stomatitis
• Gastrointestinal absorption may occur
• Corneal oedema
• Eye disorders
• Eye pain
• Palpitations

Precautions

• Monitor growth in children receiving prolonged treatment
• Consider systemic corticosteroid side effects with high doses or prolonged use

Pregnancy

Manufacturer advises only use if potential benefit outweighs the risk.

Breast-feeding

No information available-manufacturer advises only use if potential benefit outweighs risk.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Inhalation aerosol (Clenil Modulite®)
• Inhalation powder (Qvar®)

Indications

• Bacterial infections
• Sepsis
• Pneumonia
• Meningitis
• Endocarditis
• Biliary tract infections
• Prostatitis
• Surgical prophylaxis
• Acute diverticulitis
• Leg ulcer infections

Dosage

Adults: 3–5 mg/kg daily in 3 divided doses, or a single daily dose of 5–7 mg/kg adjusted according to serum-gentamicin concentration. For surgical prophylaxis, 1.5 mg/kg administered intraven

Mechanism of action

Gentamicin exerts its antibacterial effects through a multi-phase mechanism. Initially, it binds to negatively charged components of bacterial cell membranes, increasing membrane permeability. Following this, it enters the bacterial cell via energy-dependent transport mechanisms, where it binds to the 30S ribosomal subunit. This binding causes mistranslation of proteins and disrupts membrane integrity, resulting in bacterial cell death. The action is concentration-dependent, leading to rapid bactericidal effects.

Pharmacodynamics

Gentamicin has a rapid onset of action due to its mechanism of disrupting the bacterial cell membrane and inhibiting protein synthesis. Its effectiveness is enhanced by higher concentrations, and it demonstrates a post-antibiotic effect where bacteria remain suppressed even after drug levels fall below the minimum inhibitory concentration. The drug's efficacy is influenced by factors like the bacterial strain and its susceptibility patterns.

Pharmacokinetics

Gentamicin is usually administered intravenously or intramuscularly. It has a volume of distribution of approximately 0.25 L/kg and is not significantly protein-bound. The drug is primarily eliminated via renal excretion, with a half-life of 2 to 3 hours in individuals with normal renal function. Dosing adjustments are necessary in patients with renal impairment to avoid toxicity. Serum levels should be monitored to optimize therapeutic efficacy while minimizing toxicity.

Contra-indications

• Hypersensitivity to gentamicin or any aminoglycoside
• Severe renal impairment
• Pre-existing auditory or vestibular dysfunction

Adverse effects

• Ototoxicity (hearing loss, vertigo, tinnitus)
• Nephrotoxicity
• Neuromuscular blockade
• Allergic reactions (rash, pruritus)
• Injection site reactions

Interactions

• Gentamicin + relugolix: Unknown (increases exposure)
• Gentamicin + other nephrotoxic drugs (e.g., vancomycin, cisplatin): Increased risk of nephrotoxicity
• Gentamicin + neuromuscular blocking agents: Enhanced neuromuscular blockade

Precautions

• Monitor renal function during therapy, especially in patients with pre-existing renal impairment
• Caution in patients with pre-existing hearing loss or vestibular disorders
• Use with caution in pregnant women and during breastfeeding

Pregnancy

Use only if clearly needed and the benefit justifies the risk to the fetus. Limited data on use in pregnancy.

Breast-feeding

Gentamicin is excreted in breast milk, exercise caution when administering to breastfeeding mothers. Monitor infant for possible side effects.

Storage

Store below 25°C. Protect from light. Do not freeze.

Formulations

• Injection solution (various concentrations)
• Ophthalmic solution (0.3% w/v)
• Topical ointment (0.1% w/v)

Indications

• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Allergic rhinitis
• Topical treatment of inflammatory skin conditions

Dosage

Children: Dosing in children should be determined based on the BNF for Children. Refer to the BNF for specific paediatric dosing information.

Adults: The dosage for adults varies depending on the condition being treated. Refer to the BNF for specific dosing guidelines.

Mechanism of action

Beclometasone acts by binding to glucocorticoid receptors, leading to the modulation of gene expression. This results in the inhibition of pro-inflammatory cytokines and the promotion of anti-inflammatory proteins, thereby reducing inflammation and immune response.

Pharmacodynamics

As a corticosteroid, beclometasone exerts its effects by modulating various cellular functions. It decreases the migration of leukocytes to sites of inflammation, reduces capillary permeability, and inhibits the release of enzymes that contribute to the inflammatory response. The therapeutic effects are evident in conditions characterized by excessive inflammation.

Pharmacokinetics

Beclometasone is well-absorbed when administered by inhalation, and its bioavailability is significantly enhanced when delivered directly to the lungs. It undergoes extensive first-pass metabolism in the liver, which reduces systemic exposure. The half-life of beclometasone is approximately 15 hours, and it is primarily excreted via the urine as metabolites.

Contra-indications

• Hypersensitivity to beclometasone or any of its components
• Systemic fungal infections
• Active or latent tuberculosis

Adverse effects

• Local irritation
• Dryness of the throat
• Cough
• Dysphonia
• Oral candidiasis
• Adrenal suppression (with prolonged use)

Interactions

• cobicistat+beclometasone: Unknown (increases exposure)
• idelalisib+beclometasone: Unknown (increases exposure)
• clarithromycin+beclometasone: Unknown (increases exposure)

Precautions

• Use with caution in patients with active infections
• Monitor for signs of adrenal insufficiency in long-term therapy
• Consider alternate therapy in patients with a history of severe allergic reactions

Pregnancy

Beclometasone should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult a healthcare provider.

Breast-feeding

Beclometasone is excreted in breast milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Inhaler
• Nasal spray
• Topical cream
• Topical ointment

Mechanism of action

Clotrimazole acts primarily by damaging the permeability barrier in the cell membrane of fungi. Clotrimazole causes inhibition of ergosterol biosynthesis, an essential constituent of fungal cell membranes. If ergosterol synthesis is either completely or partially inhibited, the cell is no longer able to construct an intact and functional cell membrane,. Because ergosterol directly promotes the growth of fungal cells in a hormone‐like fashion, rapid onset of the above events leads to dose-dependent inhibition of fungal growth. Though decreased ergosterol, due to the inhibition of lanosterol 14-demethylase (also known as _CYP51_) is accepted to be primarily responsible for the antimycotic properties of clotrimazole, this drug also shows other pharmacological effects. These include the inhibition of sarcoplasmic reticulum Ca2+‐ATPase, depletion of intracellular calcium, and blocking of calcium‐dependent potassium channels and voltage‐dependent calcium channels. The action of clotrimazole on these targets accounts for other effects of this drug that are separate from its antimycotic activities. Clotrimazole exerts its antifungal activity by altering cell membrane permeability, apparently by binding with phospholipids in the fungal cell membrane. In contrast to polyene antibiotics (eg, amphotericin B), the action of clotrimazole is less dependent on the sterol content of the cell membrane. As a result of alteration of permeability, the cell membrane is unable to function as a selective barrier, and potassium and other cellular constituents are lost.

Pharmacodynamics

Clotrimazole is a broad-spectrum antifungal agent that inhibits the growth of pathogenic yeasts by changing the permeability of cell membranes. The action of clotrimazole is fungistatic at concentrations of drug up to 20 mcg/mL and may be fungicidal _in vitro_ against Candida albicans and other species of the genus Candida at higher concentrations. Unfortunately, resistance to clotrimazole, which was rare in the past, is now common in various patient populations. Clotrimazole is generally considered to be a fungistatic, and not a fungicidal drug, although this contrast is not absolute, as clotrimazole shows fungicidal properties at higher concentrations.

Mechanism of action

There are 3 key phases of aminoglycoside entry into cells. The first “ionic binding phase” occurs when polycationic aminoglycosides bind electrostatically to negatively charged components of bacterial cell membranes including with lipopolysaccharides and phospholipids within the outer membrane of Gram-negative bacteria and to teichoic acids and phospholipids within the cell membrane of Gram-positive bacteria. This binding results in displacement of divalent cations and increased membrane permeability, allowing for aminoglycoside entry. The second “energy-dependent phase I” of aminoglycoside entry into the cytoplasm relies on the proton-motive force and allows a limited amount of aminoglycoside access to its primary intracellular target - the bacterial 30S ribosome. This ultimately results in the mistranslation of proteins and disruption of the cytoplasmic membrane. Finally, in the “energy-dependent phase II” stage, concentration-dependent bacterial killing is observed. Aminoglycoside rapidly accumulates in the cell due to the damaged cytoplasmic membrane, and protein mistranslation and synthesis inhibition is amplified. The necessity of oxygen-dependent active transport explains why aminoglycosides are ineffective against anaerobic bacteria. Hence, aminoglycosides have both immediate bactericidal effects through membrane disruption and delayed bactericidal effects through impaired protein synthesis; observed experimental data and mathematical modeling support this two-mechanism model. Inhibition of protein synthesis is a key component of aminoglycoside efficacy. Structural and cell biological studies suggest that aminoglycosides bind to the 16S rRNA in helix 44 (h44), near the A site of the 30S ribosomal subunit, altering interactions between h44 and h45. This binding also displaces two important residues, A1492 and A1493, from h44, mimicking normal conformational changes that occur with successful codon-anticodon pairing in the A site. Overall, aminoglycoside binding has several negative effects including inhibition of translation, initiation, elongation, and ribosome recycling. Recent evidence suggests that the latter effect is due to a cryptic second binding site situated in h69 of the 23S rRNA of the 50S ribosomal subunit. Also, by stabilizing a conformation that mimics correct codon-anticodon pairing, aminoglycosides promote error-prone translation. Mistranslated proteins can incorporate into the cell membrane, inducing the damage discussed above. Aminoglycosides are usually bactericidal in action. Although the exact mechanism of action has not been fully elucidated, the drugs appear to inhibit protein synthesis in susceptible bacteria by irreversibly binding to 30S ribosomal subunits. /Aminoglycosides/ ... Aminoglycosides are aminocyclitols that kill bacteria by inhibiting protein synthesis as they bind to the 16S rRNA and by disrupting the integrity of bacterial cell membrane. Aminoglycoside resistance mechanisms include: (a) the deactivation of aminoglycosides by N-acetylation, adenylylation or O-phosphorylation, (b) the reduction of the intracellular concentration of aminoglycosides by changes in outer membrane permeability, decreased inner membrane transport, active efflux, and drug trapping, (c) the alteration of the 30S ribosomal subunit target by mutation, and (d) methylation of the aminoglycoside binding site. ... /Aminoglycosides/