Pharmacokinetics and safety of fosfluconazole after single intravenous bolus injection in healthy male Japanese volunteers

This was a single blind, placebo-controlled, escalating single-dose, three-period crossover study using two subject cohorts to investigate the safety, tolerability, and pharmacokinetics in healthy male Japanese subjects after intravenous bolus injection of fosfluconazole 50 to 2000 mg, a phosphate prodrug of fluconazole (FLCZ). Fosfluconazole was rapidly converted to FLCZ with only minor amounts excreted in the urine (less than 4% of the dose). Fosfluconazole had a volume of distribution at the higher doses, which was similar to the extracellular volume in man (0.2 L/kg) and was eliminated with a terminal half-life of 1.5 to 2.5 hours. There was apparent dose proportionality in FLCZ pharmacokinetics. C-max and AUC of FLCZ appeared to increase proportionally with increasing doses of fosfluconazole. There were no apparent dose-dependent trends in t(max), t(1/2), or mean residence time (MRT) of FLCZ. Bolus injection of fosfluconazole was well tolerated at doses of up to 2000 mg in healthy Japanese subjects.