End of the road for terbinafine? Results of a pragmatic prospective cohort study of 500 patients.

Abstract

There is a general impression among dermatologists in India that terbinafine has been losing its effectiveness in dermatophytoses over the past few years, but there are no recent data to support this. To determine the effectiveness of terbinafine in tinea corporis, tinea cruris and tinea faciei with a pragmatic prospective cohort study. A sample size of 361 patients was calculated taking a 5% margin of error and a 95% confidence level. Five hundred patients with tinea corporis, tinea cruris and tinea faciei confirmed by potassium hydroxide microscopy received oral terbinafine (5mg/kg/day) and topical terbinafine 1% applied twice daily for 4 weeks. Patients were evaluated at 2 and 4 weeks. Cure was defined as total clearance of lesions and negative microscopy. Patients who came for follow-up at 2 and 4 weeks numbered 357 and 362 respectively. Ten patients were cured at 2 weeks (cure rate 2%, 95% confidence interval 1.0-3.7%, intention-to-treat analysis) and 153 patients were cured at 4 weeks (cure rate 30.6%, 95% confidence interval 26.7-34.8%). Culture and antifungal susceptibility testing were not performed since this was a pragmatic study. There was also no follow up after completion of treatment to check for relapses, but the poor response makes this less relevant. The effectiveness of terbinafine in dermatophytosis was abysmal in this study.