The safety and pharmacokinetics of vamicamide, a new anticholinergic drug, were examined in healthy male volunteers in single- and multiple-dose studies. Twelve subjects participated in the single-dose study. Six subjects were given orally 18 mg of vamicamide and another six subjects were given 24 mg after fasting. In the multiple-dose study, nine subjects were divided into two groups of six subjects for vamicamide treatment and three subjects for placebo treatment. The subjects from active and placebo groups were given, in a single blind way, an oral dose of 12 mg of vamicamide and placebo, respectively, three times daily for five days and once on day 6. Vamicamide was well tolerated by all subjects. Clinical symptoms due to anticholinergic effect of the drug, such as dry mouth and photophobia, were observed in four and six subjects with single doses of 18 and 24 mg, respectively, and in five subjects with multiple doses of the drug. There were no abnormal findings in clinical laboratory tests, electrocardiograms or vital signs. The pharmacokinetics of vamicamide were linear. Serum concentrations of vamicamide peaked 2.6 hours after single dosing and declined with elimination half-life of 5.5 hours. Serum concentrations reached steady state by day 3 during multiple dosing. Vamicamide was extensively excreted in the urine; more than 80% of the dose was recovered unchanged in the urine. The renal clearance was 274 mL/min.