Background: The broad spectrum of activity of itraconazole in vitro manifests itself clinically with the drug being effective for the treatment of onychomycosis caused by dermatophytes, Candida and some non-dermatophyte molds. The pharmacokinetics of itraconazole in the nail results in drug remaining at therapeutic levels for 6-9 months after completion of therapy.
Methods: An overview of studies where continuous or pulse itraconazole therapy has been used in the treatment of fingernail and toenail onychomycosis.
Results: Following continuous therapy at 200 mg/day for 3 months for toenail onychomycosis (n = 1741), the rates of clinical cure, clinical response and mycologic cure were: (meta-average +/- 95% standard error (SE)), 52 +/- 9%, 86 +/- 2%, and 74 +/- 3%, respectively, at follow-up 12 months following start of therapy. In fingernail onychomycosis (n = 211), the duration of therapy was 6 weeks and the corresponding efficacy rates at follow-up, 9 months after start of therapy, were meta-average (+/- S.E.) 82 +/- 5%, 90 +/- 2%, and 86 +/- 3%, respectively. In toenail onychomycosis treated with 3 pulses of therapy (n = 1389), the clinical response, clinical cure and mycologic cure were observed in meta-average (+/- S.E.) 58 +/- 10%, 82 +/- 3%, and 77 +/- 5% patients, respectively, at follow-up 12 months after the start of therapy. In fingernail onychomycosis treated with 2 pulses of therapy (n = 210), at follow-up 9 months after the start of therapy, the corresponding efficacy rates were meta-average (+/- S.E.) 78 +/- 10%, 89 +/- 6%, and 87 +/- 8%, respectively.
Conclusions: Both the continuous and pulse therapy regimens are safe with few adverse effects. Compared to continuous therapy, the pulse regimen has an improved adverse-effects profile, is more cost-effective, and is preferred by many patients.