BACKGROUND: A problem in the treatment of onychomycosis is the lengthy duration of therapy. The pharmacokinetics of itraconazole suggest a potential for briefer treatment. OBJECTIVE: This study was designed to investigate itraconazole nail kinetics in 39 patients with onychomycosis in relation to their therapeutic outcome. METHODS: All patients received itraconazole for 3 months at a dose of 100 or 200 mg daily. Itraconazole levels of distal nail clippings were determined during a 6-month posttherapy period. RESULTS: Therapeutic itraconazole concentrations were found in the nail plates of fingernails and toenails for up to 6 months after treatment. Cure of the toenails was observed in 79% of the patients treated with the 200 mg dosage and in 26% of those treated with 100 mg at 6 months after therapy. CONCLUSION: The data suggest that the drug reaches the nail via incorporation into the matrix and by diffusion from the nail bed and is eliminated with regrowth of the nail after discontinuation of treatment.
BACKGROUND: A problem in the treatment of onychomycosis is the lengthy duration of therapy. The pharmacokinetics of itraconazole suggest a potential for briefer treatment. OBJECTIVE: This study was designed to investigate itraconazole nail kinetics in 39 patients with onychomycosis in relation to their therapeutic outcome. METHODS: All patients received itraconazole for 3 months at a dose of 100 or 200 mg daily. Itraconazole levels of distal nail clippings were determined during a 6-month posttherapy period. RESULTS: Therapeutic itraconazole concentrations were found in the nail plates of fingernails and toenails for up to 6 months after treatment. Cure of the toenails was observed in 79% of the patients treated with the 200 mg dosage and in 26% of those treated with 100 mg at 6 months after therapy. CONCLUSION: The data suggest that the drug reaches the nail via incorporation into the matrix and by diffusion from the nail bed and is eliminated with regrowth of the nail after discontinuation of treatment.