Levels of fluconazole in normal and diseased nails during and after treatment of onychomycoses in toe-nails with fluconazole 150 mg once weekly.

Thirty-six patients with onychomycoses of their toe-nails were included in a double-blind, parallel-group comparative study of fluconazole 150 mg once weekly and griseofulvin 1,000 mg once daily for 12 months, or earlier if cured. Every month during treatment and in cured patients 3 and 6 months after stop of treatment one toe-nail was clipped and serum samples were taken. In patients treated with fluconazole the concentration of fluconazole was measured in serum and nails. We found a very high concentration of fluconazole in nails (peak 8.54 micrograms/g) and the nail concentration was statistically significantly higher than serum concentrations (p < 0.001). In cured patients fluconazole was still present in high concentrations 3 (1.7 micrograms/g) and 6 (1.4 micrograms/g) months after stop of treatment. These results indicate that fluconazole should be effective in the treatment of onychomycosis in a dose of 150 mg once weekly. The results also indicate that the treatment period could be shortened because fluconazole is still present in high concentrations 6 months after stop of therapy. The concentration of fluconazole found in nails is much higher than that found in the case of terbinafine and itraconazole, indicating that fluconazole should be at least as effective as these drugs in the treatment of tinea unguium.