The pharmacokinetics of pramiracetam, a new, investigational, cognition activator, were assessed in normal male volunteers as part of a clinical tolerance study. In a double-blind, randomized design, two groups of six subjects each received alternating placebo and single 400, 800, 1,200, and 1,600 mg oral doses of pramiracetam after an overnight fast. Mean (+/- SD) peak plasma concentrations of the four dose groups (2.71 +/- 0.54, 5.40 +/- 1.34, 6.13 +/- 0.71, 8.98 +/- 0.71 micrograms/mL) were attained between two to three hours following drug administration. The harmonic mean elimination half-life (4.5-6.5 hours), the mean total body clearance (4.45-4.85 mL/min/kg), the mean renal clearance (1.83-3.00 mL/min/kg), and the mean apparent volume of distribution (1.82-2.94 L/kg) were independent of dose, whereas the peak plasma concentrations and area under the curves increased as a linear function of dose. No significant side effects were observed at any dose level.