Ketoconazole (2% w/v) is a topical antifungal agent belonging to the imidazole class. It is primarily used for the treatment of superficial fungal infections of the skin, including seborrheic dermatitis and pityriasis versicolor. It works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes, leading to increased membrane permeability and cell death. In the Indian context, it is widely available as shampoo, cream, gel, and soap formulations, with shampoo being the most common for scalp conditions.
Adult: Shampoo: Apply to wet scalp, lather, leave for 3-5 minutes, then rinse thoroughly. Use twice weekly for 2-4 weeks, then once weekly or as needed for control. Cream/Gel: Apply a thin layer to affected area once or twice daily.
Note: 1. Clean and dry the affected area before application. 2. For shampoo, use a small amount (approx. 5 ml). 3. Avoid contact with eyes, nose, mouth, and mucous membranes. 4. Do not use occlusive dressings unless directed. 5. Wash hands after application (unless hands are being treated).
Ketoconazole is a broad-spectrum synthetic antifungal. It inhibits the cytochrome P450-dependent enzyme lanosterol 14-α-demethylase. This enzyme is crucial for converting lanosterol to ergosterol, the principal sterol in fungal cell membranes. Inhibition leads to depletion of ergosterol and accumulation of toxic methylated sterol precursors, compromising membrane integrity and function.
Pregnancy: Pregnancy Category C (US FDA). Topical use is generally considered low risk as systemic absorption is minimal. Use only if the potential benefit justifies the potential risk to the fetus, especially in the first trimester. Avoid large surface areas or prolonged use.
Driving: No known effects on the ability to drive or operate machinery.
| Oral Anticoagulants (Warfarin) | Potential increased anticoagulant effect if significant systemic absorption occurs. | Moderate |
| Oral Hypoglycemics (Sulfonylureas) | Potential enhanced hypoglycemic effect. | Moderate |
| Cyclosporine, Tacrolimus | Potential increase in their blood levels if applied extensively on compromised skin. | Moderate |
| Corticosteroids (Topical) | May be used together, but sequential application is advised. No major pharmacokinetic interaction. | Minor |
Same composition (Ketoconazole (2% w/v)), different brands: