Posttreatment itraconazole levels in the nail. New implications for treatment in onychomycosis.
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.


CONCLUSIONS
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.
Willemsen
M
M
Department of Dermatology, Free University of Brussels, Jette, Belgium.
De Doncker
P
P
Willems
J
J
Woestenborghs
R
R
Van de Velde
V
V
Heykants
J
J
Van Cutsem
J
J
Cauwenbergh
G
G
Roseeuw
D
D
D000935:Antifungal Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis / Q000493:pharmacokinetics*; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D004341:Drug Evaluation; D005260:Female; D005385:Fingers; D006801:Humans; D017964:Itraconazole; D007654:Ketoconazole / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics; D008297:Male; D009262:Nails / Q000737:chemistry / Q000378:metabolism*; D014009:Onychomycosis / Q000188:drug therapy / Q000378:metabolism*; D012074:Remission Induction; D013997:Time Factors; D014034:Toes
D000935:Antifungal Agents; D002214:Capsules; D017964:Itraconazole; D007654:Ketoconazole