Treatment of Tinea Unguium with Terbinafine: An Open Study Comparing Twelve Weeks and Twenty-four Weeks of Continuous Terbinafine Therapy, and Determination of Terbinafine Level in the Target Nails

Abstract

The study protocol was approved by the Ethical Committee of Sakai Municipal Hospital. A total of 40 outpatients with tinea unguium of the toenails, fingernails or both took part after giving voluntary written informed consent. Inclusion criteria were suggestive clinical appearance, a positive KOH preparation and an opaqueness of more than 50% of the nail length. The patients received 125mg terbinafine once a day. The medication was taken after the evening meal and treatment was continued for 12 weeks. Medication stopped in twenty patients who responded well and a follow-up study was continued for 64 weeks. In the other 20 patients, medication was continued for 24 weeks and the follow-up study continued for 64 weeks. At 4-week intervals, the patients were evaluated for their clinical and mycological statuses and adverse reactions.
Clipping of distal nail samples, including any attached subungual tissue, was done using nail clippers at 4-week intervals after cessation of therapy and the level of terbinafine was measured in the laboratory. No adverse reactions were detected.
Tinea unguium of fingernails (1) and the third toes (2) were cured easily in the short term in the 12 week therapy group. One case in the 24 week therapy group was excluded because systemic steroid therapy was started for bullous pemphigoid at 32 weeks. The results of treatment of big toe onychomycosis were compared between the 12 week (17) and the 24 week (19). In the former group, 9 (52.9%) showed complete cure and 8 (47.1%) showed relapse or worse after cessation of therapy was. In 24 week therapy group, complete cure was achieved in 14 (73.7%) and relapse or worse in 5 (26.3%). The cure rate between the 2 groups was statistically not significant. Terbinafine was detected in the target nails up to 24 weeks after cessation of medication in both groups. Onychomycosis or tinea pedis reappeared in a few cases 12 to 16 weeks after medication ceased in the 12 week group. Topical antimycological therapy is necessary after cessation of oral terbinafine.