Terbinafine in the treatment of onychomycosis

Griseofulvin has been the standard therapy for dermatophyte onychomycosis, but is relatively unsuccessful, effecting a cure in only 30–40% of patients after 18 months. Of the new drugs for this indication, terbinafine (Lamisi®) appears to be the most successful. The first multicentre trial in the UK involved 103 patients receiving terbinafine at 250 mg/day for 12 and 6 months for toenail and fingernail infections, respectively; mycological cure rates were 80% and 95%, respectively. Mild gastrointestinal upset was the only reported adverse event. The relapse rate at 12 months after stopping therapy was 20%, but late cure was also seen, even in cases with Scopulariopsis infections. In a placebo-controlled trial of 12-week terbinafine treatment for nail infection at any site, mycological. cure rates were 82% and 71% for toenail and fingernail infections, respectively, in a total of 112 patients. Side-effects were again mainly gastrointestinal, but were more frequently reported with placebo. Clinical improvement was observed early in those successfully treated, allowing identification of those cases needing only 12 weeks of therapy for a good response. Terbinafine is safe and well tolerated in the treatment of dermatophyte onychomycosis, and is able to effect a cure in the majority of patients after only 12 weeks of treatment.