Special features of the clinical use of oral terbinafine in the treatment of fungal diseases.

Terbinafine (Lamisil) is an antifungal drug, belonging to a class of drugs called the allylamines, which has recently become available for clinical use. This is a report of four special features which emerged during evaluation of the systemic use of orally administered terbinafine in the treatment of 2500 patients during the last 5 years. These features include: (i) distribution of terbinafine in skin, hair and nail tissue; (ii) use in short-duration treatment of chronic tinea pedis and onychomycosis; (iii) use in patients with serious infections often associated with local or generalized immunological defects; and (iv) tolerability and safety of the drug. The diffusion of terbinafine into thickened, chronically infected tissue and into nails, and its recognized fungicidal action are the most likely features responsible for its success in the treatment of chronic fungal diseases, including those with immunological defects. Terbinafine is well tolerated, particularly when compared with other available systemic antifungal drugs.

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.