Background: Onychomycosis and dermatomycoses can result in serious complications in patients with underlying chronic diseases such as diabetes. To avoid these complications, these dermatological disorders need to be treated efficiently, for example with the triazole antifungal itraconazole. Itraconazole can inhibit the metabolism of drugs by CYP 3A4 and therefore might affect the efficacy of antidiabetic agents.
Objective: To investigate this, we assessed the safety of itraconazole in diabetic patients with onychomycosis or dermatomycoses.
Methods: We reviewed pharmacokinetic and safety data from clinical trials and postmarketing surveillance over the past 10 years.
Results: Postmarketing surveillance (a review of all adverse-event reports in patients receiving itraconazole concomitantly with insulin or an oral antidiabetic agent) revealed 15 reports suggestive of hyperglycemia and 9 reports suggestive of hypoglycemia; in most patients, no change in antidiabetic effect was reported. From clinical trials including a total of 189 diabetic patients treated with itraconazole for various infections (mainly systemic infections and vaginal candidiasis), only one itraconazole-related adverse event was recorded; this was a case of aggravated diabetes in a renal transplant recipient who was also receiving cyclosporine. Adverse effects due to drug-drug interactions are not expected in diabetic patients receiving oral antidiabetic agents that are not metabolized through the CYP 3A4 system (e.g. tolbutamide, gliclazide, glibenclamide, glipizide and metformin).
Conclusion: Itraconazole can be used safely and efficiently for the treatment of dermatological disorders in diabetic patients.