Pharmacokinetics of benperidol in volunteers after oral administration

Benperidol in a 4 mg single dose was administered orally to five healthy male volunteers. The drug was rapidly absorbed (tmax = 2.27 +/- 0.57 h) and largely distributed, the volume of distribution being 5.19 +/- 1.99 l.kg-1. Elimination half-life was 7.65 +/- 2.14 h. Urinary excretion represented only a minimal fraction of ingested dose (0.1 +/- 0.007%). Variability of the area under the curve makes a first-pass metabolism a reasonable possibility. Acute dystonias appeared in two subjects.