Clotrimazole is a broad-spectrum synthetic imidazole antifungal agent used topically for the treatment of superficial fungal infections. At 2% w/w concentration, it is a standard strength for creams, lotions, and powders, primarily effective against dermatophytes, yeasts (including Candida albicans), and Malassezia furfur. It works by inhibiting ergosterol synthesis, a critical component of fungal cell membranes.
Adult: Apply a thin layer to affected and surrounding skin 2-3 times daily. For vaginal candidiasis: 1 applicatorful of 2% cream or 1 vaginal tablet (100mg) intravaginally at bedtime for 3-7 nights.
Note: Clean and dry the affected area thoroughly before application. Wash hands before and after use. For skin: Gently massage until absorbed. For vagina: Use applicator provided and insert at bedtime. Continue treatment for the full prescribed duration, even if symptoms improve earlier. Do not use occlusive dressings unless advised.
Clotrimazole acts primarily by inhibiting the fungal cytochrome P450-dependent enzyme lanosterol 14-α-demethylase. This inhibition blocks the conversion of lanosterol to ergosterol, an essential sterol component of the fungal cell membrane. Depletion of ergosterol and accumulation of toxic methylated sterols disrupts membrane structure and function, increasing permeability and leakage of cellular components, leading to fungal cell death.
Pregnancy: Pregnancy Category B (US FDA). Considered safe for topical use in limited areas. For vulvovaginal candidiasis, topical azoles like clotrimazole are preferred treatment in the 2nd and 3rd trimesters. Use in the first trimester should be based on physician judgment, preferring shorter courses. Avoid vaginal applicator trauma.
Driving: No effect on ability to drive or operate machinery.
| Amphotericin B | Potential antagonism of antifungal effect (based on in-vitro data). Clinical significance for topical use is minimal. | Moderate |
| CYP3A4 substrates (e.g., Terfenadine, Astemizole - withdrawn) | Theoretical interaction if significant systemic absorption occurs, leading to increased levels of the substrate. Not relevant with standard topical use. | Low |
| Other topical corticosteroids (e.g., Betamethasone, Hydrocortisone in combination products) | Corticosteroid may mask symptoms of infection or cause skin atrophy with prolonged use. Fixed-dose combinations are common in India. | Moderate |