Terbinafine (Lamisil®) in the treatment of onychomycosis

Terbinafine is a broad-spectrum antifungal agent effective in many different fungal diseases. Its fungicidal effect in vitro is confirmed by several in vivo studies, including a multicentre study of 80 patients with toenail onychomycosis in which terbinafine achieved 82% mycological cure. Twelve weeks has been established as the optimal treatment duration for toenail infection and 6 weeks for fingernail infection. The recommended dose worldwide is 250 mg daily, except in Japan, where 125 mg daily is used for twice the treatment time. Several double-blind, parallel-group studies comparing terbinafine with griseofulvin, itraconazole and fluconazole in the treatment of onychomycosis in both toenail and fingernail disease have shown that terbinafine is significantly more efficacious, as well as cost-effective. A pharmacoeconomic study found terbinafine to be more cost-effective in the management of dermatophyte onychomycosis than griseofulvin, itraconazole or ketoconazole. Minor gastrointestinal effects occur in around 5% of patients, skin reactions in 2% and reversible taste disturbance in less than 1% of patients. Hepatic injury in about 1 in 50000 patients, but nor necessarily in patients with pre-existing liver disease. The clinical studies suggest that terbinafine should be considered the treatment of choice in dermatophyte onychomycosis.