Background: Diabetes mellitus (DM) affects an estimated 175 million people world-wide. Approximately one-third of patients with DM have toenail onychomycosis.
Objectives: To determine the efficacy and safety of terbinafine treatment of toenail onychomycosis in patients with DM receiving insulin and/or oral antidiabetic agents. Special interest was focused on potential drug interactions with oral hypoglycaemic substances.
Methods: In a multicentre trial, patients suffering from insulin-dependent DM (IDDM) or non- insulin-dependent DM (NIDDM) with toenail onychomycosis were treated for 12 weeks with oral terbinafine 250 mg daily and followed up to 48 weeks. In addition to clinical, mycological and laboratory investigations, blood glucose levels were monitored.
Results: At the end of the trial (week 48), a mycological cure rate of 73% was achieved. The rates of clinical cure and complete cure (mycological cure plus clinical cure) were 57% and 48%, respectively. There was no statistically significant difference between the NIDDM and IDDM groups with respect to the cure rates (P > 0.05). No hypoglycaemic episode was reported and none of the patients had hypoglycaemia during the treatment phase.
Conclusions: With excellent cure rates and a good tolerability profile, terbinafine should continue to be a drug of choice for the treatment of toenail onychomycosis in the rising number of NIDDM patients receiving multiple medication.