Objective: To examine long-term cure and relapse rates after treatment with continuous terbinafine and intermittent itraconazole in onychomycosis.
Design: Long-term prospective follow-up study.
Setting: Three centers in Iceland.
Subjects: The study population comprised 151 patients aged 18 to 75 years with a clinical and mycological diagnosis of dermatophyte toenail onychomycosis.
Interventions: In a double-blind, double-dummy study, patients were randomized to receive either terbinafine (250 mg/d) for 12 or 16 weeks or itraconazole (400 mg/d) for 1 week in every 4 for 12 or 16 weeks (first intervention). Patients who did not achieve clinical cure at month 18 or experienced relapse or reinfection were offered an additional course of terbinafine (second intervention).
Main outcome measures: The primary efficacy criterion was mycological cure, defined as negative results on microscopy and culture at the end of follow-up and no requirement of second intervention treatment. Secondary efficacy criteria included clinical cure without second intervention treatment and mycological and clinical relapse rates.
Results: Median duration of follow-up was 54 months. At the end of the study, mycological cure without second intervention treatment was found in 34 (46%) of the 74 terbinafine-treated subjects and 10 (13%) of the 77 itraconazole-treated subjects (P<.001). Mycological and clinical relapse rates were significantly higher in itraconazole vs terbinafine-treated patients (53% vs 23% and 48% vs 21%, respectively). Of the 72 patients who received subsequent terbinafine treatment, 63 (88%) achieved mycological cure and 55 (76%) achieved clinical cure.
Conclusion: In the treatment of onychomycosis, continuous terbinafine provided superior long-term mycological and clinical efficacy and lower rates of mycological and clinical relapse compared with intermittent itraconazole.