Safi

Indications

• Vaginal candidiasis
• Vulval candidiasis
• Superficial fungal infections

Dosage

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

Adults: For vaginal candidiasis, 1 pessary or 5 g of cream should be applied intravaginally at night for at least 14 days, with the course possibly repeated if necessary. For vulval candidiasis, apply cream 2-3 times a day to the affected area for the same duration.

Mechanism of action

Econazole nitrate exerts its antifungal effects by inhibiting the enzyme lanosterol 14-alpha-demethylase, which is crucial for the conversion of lanosterol to ergosterol in the fungal cell membrane. This disruption in ergosterol synthesis compromises the structural integrity of the fungal cell membrane, leading to increased permeability, cell lysis, and ultimately, cell death.

Pharmacodynamics

Econazole exhibits broad-spectrum antifungal activity against various fungi, including Candida species and dermatophytes. It is effective in treating superficial fungal infections due to its ability to penetrate the skin and mucosal tissues. The drug's effectiveness is enhanced when used consistently over the recommended treatment duration, which is typically at least 14 days for most infections.

Pharmacokinetics

Econazole is primarily administered topically, leading to minimal systemic absorption. When applied to the skin or vaginal mucosa, it achieves localized concentrations sufficient for antifungal activity. The pharmacokinetics of econazole indicate a high degree of binding to skin and mucosal tissues, allowing for sustained release and prolonged antifungal action. The elimination half-life is not well defined due to its local application and limited systemic exposure.

Contra-indications

• Hypersensitivity to econazole nitrate or any of the excipients
• Pregnancy, particularly during the first trimester

Adverse effects

• Skin reactions
• Vaginal burning
• Angioedema

Interactions

• May damage latex condoms and diaphragms

Precautions

• Use with caution in patients with a history of hypersensitivity reactions
• Monitor for skin reactions
• Avoid use during the first trimester of pregnancy

Pregnancy

Oral antifungal treatments should be avoided during pregnancy. Pregnant women may need a longer duration of treatment, usually about 7 days, to clear the infection.

Breast-feeding

Limited data available, but caution is advised as econazole may be excreted in breast milk.

Storage

Store below 25 degrees Celsius. Keep the container tightly closed and protect from light.

Formulations

• Econazole nitrate 10 mg per 1 gram cream
• Econazole nitrate vaginal pessaries

Indications

• Eczema
• Psoriasis
• Contact dermatitis
• Allergic dermatitis
• Seborrheic dermatitis

Dosage

Children: Refer to specific product information or clinical guidelines for appropriate dosing in children, as it varies by formulation and condition treated.

Adults: Refer to specific product information or clinical guidelines for appropriate dosing, as it varies by formulation and condition treated.

Mechanism of action

Acetonide exerts its effects by binding to glucocorticoid receptors in the cytoplasm of target cells, leading to the translocation of the receptor-ligand complex into the nucleus. This complex then influences the expression of specific genes, resulting in decreased production of pro-inflammatory cytokines and increased production of anti-inflammatory proteins. This modulation of gene expression contributes to its anti-inflammatory and immunosuppressive effects.

Pharmacodynamics

The pharmacodynamics of acetonide involve its ability to inhibit the migration of leukocytes to sites of inflammation, reduce the production of inflammatory mediators such as prostaglandins and leukotrienes, and suppress the immune response. The potency and duration of action can vary based on the specific formulation and concentration used.

Pharmacokinetics

Acetonide is absorbed through the skin when applied topically, with systemic absorption depending on the formulation, application area, and duration of use. It undergoes hepatic metabolism, and its metabolites are excreted primarily through the urine. The half-life and clearance rates can vary based on individual patient factors and specific formulations.

Contra-indications

• Hypersensitivity to acetonide or any component of the formulation.
• Active or untreated infections at the site of application.

Adverse effects

• Local irritation or burning sensation at the application site.
• Skin thinning or atrophy with prolonged use.
• Systemic effects such as adrenal suppression with high doses or prolonged therapy.

Interactions

• Increased risk of systemic effects when used with other corticosteroids.
• Potentially altered metabolism when administered with CYP3A4 inhibitors or inducers.

Precautions

• Use with caution in patients with a history of tuberculosis or other infections.
• Monitor for signs of adrenal insufficiency in patients on high doses.
• Avoid application to large areas of the body or under occlusive dressings.

Pregnancy

Acetonide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult with a healthcare professional before use.

Breast-feeding

Limited data available. Use with caution as it may be excreted in breast milk. Consult with a healthcare professional before use.

Storage

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

Formulations

• Topical cream
• Topical ointment
• Topical solution

Indications

• Tinea pedis (athlete's foot)
• Tinea cruris (jock itch)
• Tinea corporis (ringworm)
• Candidiasis (yeast infections)
• Dermatophyte infections

Dosage

Children: For children, refer to the BNF for Children for appropriate dosing information.

Adults: Apply to the affected area once daily for 2 to 4 weeks, depending on the specific infection being treated.

Mechanism of action

Econazole interacts with 14-alpha demethylase, a cytochrome P-450 enzyme necessary for converting lanosterol to ergosterol. Inhibition of ergosterol synthesis results in increased cellular permeability and leakage of cellular contents. Additionally, econazole may inhibit endogenous respiration, interact with membrane phospholipids, inhibit the transformation of yeasts to mycelial forms, inhibit purine uptake, and impair triglyceride and/or phospholipid biosynthesis.

Pharmacodynamics

Econazole is an antifungal agent related to other azoles such as fluconazole, ketoconazole, itraconazole, and clotrimazole. It prevents fungal organisms from producing vital substances required for their growth and function, making it effective only against fungal infections.

Pregnancy

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

Breast-feeding

Econazole may be excreted in human breast milk, use caution when administering to nursing mothers.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Topical cream
• Topical solution
• Vaginal cream

Indications

• Severe infections caused by Gram-negative bacteria
• Urinary tract infections
• Bacteremia
• Sepsis
• Pneumonia
• Intra-abdominal infections
• Skin and soft tissue infections

Dosage

Adults: The usual dosage for adults is 3 to 5 mg/kg/day divided into 3 doses, given intravenously or intramuscularly. Adjustments should be made based on renal function and severity of infection.

Mechanism of action

Gentamicin acts by binding to the bacterial 30S ribosomal subunit, leading to misreading of mRNA and subsequent production of nonfunctional or toxic peptides. This disrupts protein synthesis and leads to bacterial cell death. The drug enters bacterial cells in a three-phase process: first, ionic binding occurs with the cell membrane, increasing permeability. Second, energy-dependent transport allows the drug to access its intracellular target. Third, concentration-dependent killing is observed as gentamicin accumulates within the cell, amplifying its effects on protein synthesis and membrane integrity.

Pharmacodynamics

Gentamicin exhibits concentration-dependent bactericidal activity, meaning that its efficacy increases with higher concentrations. The pharmacodynamic properties highlight the rapid and delayed bactericidal effects, with membrane disruption occurring immediately followed by impaired protein synthesis. The drug's action is particularly effective against aerobic Gram-negative bacteria, while its effectiveness is significantly reduced in anaerobic conditions.

Pharmacokinetics

Gentamicin is poorly absorbed from the gastrointestinal tract; thus, it is typically administered intravenously or intramuscularly. It has a volume of distribution that reflects extensive tissue penetration, particularly in renal and gastrointestinal tissues. The elimination half-life ranges from 2 to 3 hours in healthy individuals, but it can be prolonged in patients with renal impairment. The drug is primarily eliminated by renal excretion, with dosage adjustments required in cases of renal dysfunction.

Contra-indications

• Hypersensitivity to gentamicin or other aminoglycosides
• Severe renal impairment
• Myasthenia gravis

Adverse effects

• Nephrotoxicity
• Ototoxicity (hearing loss, balance disorders)
• Neuromuscular blockade
• Allergic reactions (rash, pruritus)
• Peripheral neuropathy

Interactions

• Increased risk of nephrotoxicity with other nephrotoxic agents (e.g., cisplatin, vancomycin)
• Increased risk of ototoxicity with loop diuretics (e.g., furosemide)
• Synergistic effects with beta-lactam antibiotics

Precautions

• Monitor renal function during treatment
• Use caution in patients with pre-existing hearing loss
• Adjust dosage in patients with renal impairment
• Consider potential drug interactions

Pregnancy

Gentamicin should be used during pregnancy only if clearly needed, due to potential risk of fetal harm.

Breast-feeding

Gentamicin is excreted in breast milk, but is generally considered safe. Monitor for possible effects on the infant.

Storage

Store in a cool, dry place, away from light. Do not refrigerate or freeze.

Formulations

• Injection (solution for injection)
• Topical ointment
• Eye drops

Indications

• Asthma
• Allergic rhinitis
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Dermatitis
• Psoriasis
• Inflammatory bowel disease

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on condition and formulation.

Adults: Refer to BNF for specific dosing recommendations based on condition and formulation.

Mechanism of action

Triamcinolone inhibits phospholipase A2 on cell membranes, preventing the breakdown of lysosomal membranes of leukocytes. This action reduces the formation of arachidonic acid, leading to decreased expression of cyclooxygenase and lipoxygenase, which inhibits the synthesis of prostaglandins and leukotrienes. Additionally, triamcinolone inhibits nuclear factor kappa-B, reducing pro-inflammatory signals such as interleukin-6 and interleukin-8. It interacts with specific intracellular receptor proteins to alter the expression of corticosteroid-responsive genes, leading to the synthesis of proteins like lipocortin that further inhibit inflammatory pathways.

Pharmacodynamics

Triamcinolone exhibits significant anti-inflammatory effects through multiple mechanisms, including suppression of immune cell migration and modulation of inflammatory mediator production. Its effects can lead to reduced edema, erythema, and pain associated with inflammatory processes. The drug’s action is mediated by its ability to influence gene expression in target tissues, resulting in a broad range of effects on the immune response and inflammation.

Pharmacokinetics

Triamcinolone is well absorbed following parenteral administration, with peak plasma concentrations typically observed within a few hours. It has a relatively long half-life, which allows for sustained therapeutic effects. The drug is metabolized primarily in the liver and excreted via the kidneys. Its pharmacokinetic profile may vary depending on the route of administration and the specific formulation used.

Interactions

• mitotane+triamcinolone: Moderate (decreases exposure)
• rifampicin+triamcinolone: Moderate (decreases exposure)
• cobicistat+triamcinolone: Unknown (increases exposure)
• idelalisib+triamcinolone: Unknown (increases exposure)
• clarithromycin+triamcinolone: Unknown (increases exposure)

Pregnancy

Corticosteroids, including triamcinolone, should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. They may cause fetal harm, particularly when used in high doses or for prolonged periods in the second and third trimesters.

Breast-feeding

Triamcinolone is excreted in human milk, and caution should be exercised when administering to nursing mothers. The benefits of breastfeeding should be weighed against the potential risk of adverse effects on the infant.

Storage

Store at room temperature, away from light and moisture. Do not freeze.

Mechanism of action

Econazole interacts with 14-α demethylase, a cytochrome P-450 enzyme necessary to convert lanosterol to ergosterol. As ergosterol is an essential component of the fungal cell membrane, inhibition of its synthesis results in increased cellular permeability causing leakage of cellular contents. Econazole may also inhibit endogenous respiration, interact with membrane phospholipids, inhibit the transformation of yeasts to mycelial forms, inhibit purine uptake, and impair triglyceride and/or phospholipid biosynthesis.

Pharmacodynamics

Econazole is an antifungal medication related to fluconazole (Diflucan), ketoconazole (Nizoral), itraconazole (Sporanox), and clotrimazole (Lotrimin, Mycelex). Econazole prevents fungal organisms from producing vital substances required for growth and function. This medication is effective only for infections caused by fungal organisms. It will not work for bacterial or viral infections.

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/

Mechanism of action

Corticosteroids like triamcinolone inhibit phospholipase A2 on cell membranes, preventing the breakdown of lysosomal membranes of leukocytes, which in turn prevent the formation of arachidonic acid, which decrease expression of cyclooxygenase and lipoxygenase, inhibiting synthesis of prostaglandins and leukotrienes. Anti-inflammatory activity occurs via reversal of vascular dilation and reducing permeability, which prevents macrophage and leukocyte migration. Triamcinolone also inhibits nuclear factor kappa-B, which decreases the production of pro-inflammatory signals such as interleukin-6, interleukin-8, and monocyte chemoattractant protein-1. Glucocorticoids are capable of suppressing the inflammatory process through numerous pathways. They interact with specific intracellular receptor proteins in target tissues to alter the expression of corticosteroid-responsive genes. Glucocorticoid-specific receptors in the cell cytoplasm bind with steroid ligands to form hormone-receptor complexes that eventually translocate to the cell nucleus. There these complexes bind to specific DNA sequences and alter their expression. The complexes may induce the transcription of mRNA leading to synthesis of new proteins. Such proteins include lipocortin, a protein known to inhibit PLA2a and thereby block the synthesis of prostaglandins, leukotrienes, and PAF. Glucocorticoids also inhibit the production of other mediators including AA metabolites such as COX, cytokines, the interleukins, adhesion molecules, and enzymes such as collagenase. /Glucocorticoids/ Corticosteroids diffuse across cell membranes and complex with specific cytoplasmic receptors. These complexes then enter the cell nucleus, bind to DNA (chromatin), and stimulate transcription of messenger RNA (mRNA) and subsequent protein synthesis of various inhibitory enzymes responsible for the anti-inflammatory effects of topical corticosteroids. These anti-inflammatory effects include inhibition of early processes such as edema, fibrin deposition, capillary dilatation, movement of phagocttes into the area, and phagocytic activities. Later processes, such as capillary production, collagen deposition, and keloid formation also are inhibited by corticosteroids. The overall actions of topical corticosteroids are catabolic. /Corticosteroids (topical)/ The potent anti-inflammatory action may be due to an inhibition of the secretion of growth factors, endothelial activating and other cytokines from lymphocytes, eosinophils, macrophages, fibroblasts, and mast cells. The results are decreased influx of inflammatory cells into the bronchial walls, due in part to inhibition of expression of adhesion molecules on the endothelium and in the tissue. Decreased activation and survival of eosinophils in the lung tissue and a reduction in numbers of mast cells are further effects. Corticosteroids may inhibit release of mediators from basophils and enzymes from macrophages. There is decreased permeability through vasoconstriction and direct inhibition of endothelial cell contradiction. Beta-adrenergic-receptor numbers may be increased, which results in an enhanced response to beta-adrenergic bronchodilators and reduced down-regulation of beta-receptors after prolonged beta-agonist exposure. Inhaled corticosteroids also inhibit mucus secretion in airways, possibly by a direct action on submucosal gland cells and an indirect inhibitory effect caused by the reduction in inflammatory mediators that stimulate mucus secretion. The amount and viscosity of sputum are reduced. /Corticosteroids (inhalation-local/

Pharmacodynamics

Triamcinolone is a corticosteroid with anti-inflammatory properties. These properties are used to treat inflammation in conditions that affect various organs and tissues. Triamcinolone should not be administered as an epidural injection.