Abstract
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 primary responsible for the problems in Vesparax intoxication.