Peculiar pharmacokinetics of brallobarbital as a source of complications in Vesparax intoxication.

1. The rate of elimination of brallobarbital, a component of Vesparax depends on the route of administration. The half-life following oral administration is considerably longer than after intravenous injection. This corresponds with longer sleeping times. 2. The half-life of brallobarbital administered intravenously could be increased by administration of its metabolites. This suggests that a metabolite, formed especially after oral administration, is responsible for the retarded elimination of brallobarbital. 3. The presence of the other components of Vesparax, namely secobarbital and hydroxyzine also increases the half-life of brallobarbital. 4. Brallobarbital, rather than the other components of Vesparax is primarily responsible for the problems in Vesparax intoxication.