Clinical efficacy and tolerability of terbinafine (Lamisil)--a new topical and systemic fungicidal drug for treatment of dermatomycoses.

Terbinafine (Lamisil) is the newest compound within a class of antimycotic drugs called allylamines. It is active against a broad range of dermatophytes and yeasts and exerts its fungicidal action by inhibiting squalene epoxidation during sterol synthesis in fungal membranes. Effective therapy (complete cure or mycological cure with minimal signs and symptoms) has been observed in 70-90% of 1200 patients treated topically with 1% cream for tinea corporis/cruris, tinea pedis, cutaneous candidiasis and pityriasis versicolor. Cure in patients treated systemically (125 mg b.i.d. orally) has been documented to be 75-90% in tinea corporis and chronic tinea pedis (plantar type), 60-70% in cutaneous candidiasis, and 90-100% in onychomycosis. Particularly noteworthy is the low rate of relapse of infection after cure of chronic dermatophyte infections, since frequent relapse is a recognized problem with presently available antifungal drugs. Terbinafine is ineffective when used systemically for pityriasis versicolor. Side-effects following oral administration of the recommended dose of 125 mg b.i.d. include gastrointestinal symptoms (3-4%), allergy (1%), and miscellaneous mild non-specific symptoms (1%). No significant haematological, hepatic or renal effects have been observed. Based on the drug's fungicidal action and the early appearance of negative cultures in these studies, a short duration therapy is predicted to be effective.