ANTAGONISM OF IMIPRAMINE POISONING BY ANTICONVULSANTS IN RAT

Dose-response curves were obtained in male Wistar rats for imipramine-induced convulsions and death. For i.p. administration, the median convulsive dose (CD50) (64.7 mg/kg) was only slightly lower than the LD50 (85.8 mg/kg). The calculated LD90 (112 mg/kg) was used to test the effectiveness of diazepam, phenytoin or phenobarbital in preventing imipramine seizures. Imipramine convulsions could be prevented by either diazepam or phenobarbital but not by phenytoin (5-200 mg/kg i.p.). The i.p. median preventive dose (PD50) for diazepam was estimated to be 0.32 mg/kg, and for phenobarbital, 17.6 mg/kg.