Iontophoretic delivery of terbinafine in onychomycosis: a preliminary study

Background Onychomycosis is a common disease; topical treatment is usually poorly effective, while systemic treatment is more effective but may be associated with side-effects. Iontophoretic drug delivery may improve drug penetration through the nail and lead to better therapeutic results. Objectives To evaluate the efficacy, safety and tolerability of topical treatments with terbinafine HCl delivered with or without an iontophoretic patch in patients with onychomycosis of the toenails. Methods Patients enrolled into the study were divided randomly into two groups. Group A was treated with terbinafine and an iontophoretic patch (at a constant current density of 100 microA cm(-2)). Group B was treated with terbinafine without iontophoresis. Treatment was overnight wear, every day, 5 days per week, for 4 weeks. Follow-up period was 8 weeks from the end of treatment. Results A significant clinical response was recorded in patients of group A (active group). The percentage of patients having healthy toenail growth of more than 1.5 mm at the end of treatment was 40% compared with 11% in patients treated with terbinafine without current (passive group). The percentage of patients having fungal elements (KOH) in nail specimens decreased significantly at 8 weeks following the completion of treatment: 16% in the active group vs. 53% in the passive group. Patients in the active group reported a tingling sensation that is expected when using an iontophoretic drug delivery treatment. Conclusions The delivery of terbinafine under an electrical current of 100 microA cm(-2) appears to be efficacious and safe and is well tolerated for the treatment of nail onychomycosis.