Safety of itraconazole pulse therapy for onychomycosis. An update

After experience with more than 34 million patients over 10 years, the safety of itraconazole and its potential drug-drug interactions are well known. In clinical trials, the average incidence of adverse events with a 1-week pulse regimen was 18% in pooled safety data (n = 2,867); only 2.2% of patients dropped out. In direct comparative trials, the incidence of mild and reversible adverse effects was comparable for itraconazole and terbinafine (31% and 28%, respectively) during treatment. The rate of permanent withdrawal because of adverse events was 3.6% for itraconazole and 7.5% for terbinafine (P < .05). Itraconazole was significantly better tolerated as evaluated by the investigator and patients. The analysis of the elderly subpopulation showed that patients 65 and older tolerated itraconazole pulse well, with only 20% experiencing mild and reversible side effects (total group). In direct comparative trials, itraconazole also produced fewer adverse effects than terbinafine (13% vs 32%, respectively). As newer oral antifungal agents gain widespread use, clinicians need to be aware of their potential drug-drug interactions and their possibly serious adverse events. However, pooled data from the 1-week itraconazole pulse regimen indicated a favorable safety profile, and a dose increase to 400 mg had no impact on safety.

A multicenter, placebo-controlled, double-blind study of intermittent therapy with itraconazole for the treatment of onychomycosis of the fingernail

BACKGROUND

Onychomycosis is the most frequent cause of nail disease and represents 30% of all mycotic infections of the skin.

OBJECTIVE

Our purpose was to compare the effectiveness and tolerability of intermittent dosing of itraconazole ("pulse therapy") with placebo in fingernail onychomycosis.

METHODS

Seventy-three patients with clinically and mycologically diagnosed fingernail onychomycosis were randomly selected to receive itraconazole, 200 mg twice daily, or placebo for the first week of each month for 2 consecutive months; patients were observed for 19 weeks. Seventy-one patients received the study medication and were included in the safety analysis. Efficacy of treatment was evaluated in 46 patients.

RESULTS

A significantly greater proportion of itraconazole-treated patients than placebo-treated patients achieved clinical success (77% vs 0%), mycologic success (73% vs 13%), and overall success (68% vs 0%). No itraconazole-treated patient had a clinical or mycologic relapse during the follow-up period. Ten itraconazole-treated patients (28%) and nine placebo-treated patients (26%) had adverse events. Three patients discontinued treatment for safety reasons.

CONCLUSION

Pulse therapy with itraconazole for 2 consecutive months produces significantly greater clinical, mycologic, and overall success than placebo. Short-term itraconazole pulse therapy for fingernail onychomycosis is effective and well tolerated.