Pharmacokinetics of eltoprazine in healthy male subjects after single dose oral and intravenous administration.

The kinetics, safety and tolerability of eltoprazine hydrochloride were studied in an open, cross-over, partially randomised design after single oral (8 mg) and intravenous (3 and 8 mg) doses to 12 healthy male subjects. After intravenous administration, the mean t1/2 ranged from 7 to 9 h, the MRT was 11 h, CL was 487 +/- 148 (3 mg dose) and 471 +/- 56 (8 mg dose) ml kg-1 h-1, while CLR was 226 +/- 124 (3 mg dose) and 189 +/- 38 (8 mg dose) ml kg-1 h-1. The Vss was 3.3 +/- 0.7 (3 mg dose) and 3.8 +/- 0.5 (8 mg dose) 1 kg-1. Cumulative renal excretion was 40%. The AUC and the cumulative urinary excretion were directly proportional to dose within the range of 3-8 mg. Values of tmax varied from 1 to 4 h after oral administration. The mean Cmax value was 24 ng ml-1 after an oral dose of 8 mg. The plasma elimination half-life after oral administration was 9.8 +/- 3.9 h. Absolute oral bioavailability was 110 +/- 32%. Dose-dependent somnolence was observed.