Double blind, randomised study of continuous terbinafine compared with intermittent itraconazole in treatment of toenail onychomycosis. The LION Study Group.

OBJECTIVE To compare the efficacy and safety of continuous terbinafine with intermittent itraconazole in the treatment of toenail onychomycosis. DESIGN Prospective, randomised, double blind, double dummy, multicentre, parallel group study lasting 72 weeks. SETTING 35 centres in six European countries. SUBJECTS 496 patients aged 18 to 75 years with a clinical and mycological diagnosis of dermatophyte onychomycosis of the toenail. INTERVENTIONS Study patients were randomly divided into four parallel groups to receive either terbinafine 250 mg a day for 12 or 16 weeks (groups T12 and T16) or itraconazole 400 mg a day for 1 week in every 4 weeks for 12 or 16 weeks (groups I3 and I4). MAIN OUTCOME MEASURES Assessment of primary efficacy at week 72 was mycological cure, defined as negative results on microscopy and culture of samples from the target toenail. RESULTS At week 72 the mycological cure rates were 75.7% (81/107) in the T12 group and 80. 8% (80/99) in the T16 group compared with 38.3% (41/107) in the I3 group and 49.1 % (53/108) in the I4 group. All comparisons (T12 v I3, T12 v I4, T16 v I3, T16 v I4) showed significantly higher cure rates in the terbinafine groups (all P<0.0001). Also, all secondary clinical outcome measures were significantly in favour of terbinafine at week 72. There were no differences in the number or type of adverse events recorded in the terbinafine or itraconazole groups. CONCLUSION Continuous terbinafine is significantly more effective than intermittent itraconazole in the treatment of patients with toenail onychomycosis.