Treatment of onychomycosis with terbinafine.

An open multicentre trial was conducted by 40 dermatologists in Switzerland involving 188 patients with onychomycosis of either the toenails or fingernails. Of these patients, 145 who had positive microscopy and culture of dermatophyte infection were evaluable: of the dermatophytes identified at the initial visit, 80% were Trichophyton rubrum and 12.4% were T. mentagrophytes. Only the most affected nail was evaluated during the observation period. Daily dosage was 250 mg of terbinafine (Lamisil) orally for up to 6 months. The cure rate (negative microscopy and culture) at the end of treatment was 77% for toenails and 100% for fingernails. A follow-up investigation was made 6 months after the end of treatment: of the 88 patients examined with onychomycosis of the toenail and the 14 with fingernail onychomycosis, 90.9% and 85.7%, respectively, remained free of recurrence. Of the 26 patients who had shown improvement, but not cure, by the end of the treatment period, 15 were clinically and mycologically cured at the time of the follow-up investigation. Terbinafine was generally well tolerated; the most frequent drug-related adverse events were mild-to-moderate gastrointestinal disturbances. Changes in liver or renal biochemical tests were not considered clinically relevant.