Terbinafiini

Terbinafine, marketed under various brand names such as Lamisil, is an allylamine antifungal agent used to treat fungal infections of the skin and nails. In Italian, the drug is called terbinafina.

It acts by inhibiting squalene epoxidase, an enzyme in ergosterol synthesis. This leads to reduced ergosterol in fungal membranes and accumulation of toxic squalene, which is fungicidal for dermatophytes.

Terbinafine is used topically for tinea pedis, tinea corporis, and tinea cruris. The oral formulation is indicated for onychomycosis (nail infections) and tinea capitis, with systemic therapy typically reserved for more persistent infections.

Topical terbinafine is usually applied as a 1% cream to the affected area once or twice daily for 1–4 weeks, depending on the site and severity. Oral therapy is commonly 250 mg once daily for about 6–12 weeks for nails.

Most people tolerate terbinafine well. Common side effects include gastrointestinal upset, headache, and taste disturbance. Rare but serious hepatotoxicity has been reported; liver function monitoring is advised for long courses or underlying liver disease.

Contraindications include active liver disease. Safety in pregnancy and breastfeeding is not established; topical use is generally preferred in pregnancy. Terbinafine can interact with medications metabolized by CYP2D6, and may increase levels of certain antidepressants, antipsychotics, and beta-blockers.

Resistance is uncommon but may involve mutations in the fungal SQLE gene encoding squalene epoxidase. Terbinafine was developed in the 1980s and approved for use in the 1990s; it remains a widely used antifungal agent.