[Calcium channel modulators as antidotes in fatal imipramine poisoning]. / Effets antidotes de certains modulateurs des canaux calciques dans l'intoxication létale à l'imipramine.

Calcium entry modulators were tested as antidotes to imipramine lethal toxicity. 42 rats were administered intraperitoneally 85 mg/kg of imipramine. In 6 control rats, hypotension and bradycardia were observed. Survival time was 15' +/- 5'. Survival time of rats treated with intraarterial nitrendipine was 21' +/- 11'. Survival time of 5 out of 6 rats treated by intraarterial verapamil or diltiazem was respectively 19'00" +/- 14'30" and 40'30" +/- 32'00". 5 out of 6 rats treated by intraarterial nimodipine, as well as all of the rats treated by flunarizine or nicardipine survived and were alive and active 48 hours later. Intoxication with imipramine may induce life threatening complications for which there are no specific medication. Nicardipine might be considered in the treatment of acute poisoning by imipramine and related tricyclic compounds.

Effect of ovariectomy and estrogen on [3H]imipramine binding to different regions of rat brain.

In rats, 35 days after ovariectomy, the number of [3H]imipramine binding sites increased more than 200% in striatum, hippocampus and hypothalamus but it did not change in cerebral cortex and brain-stem. Estradiol-17 beta acting in vitro inhibited [3H]imipramine binding in control membranes of striatum, hippocampus and hypothalamus, but not in the same regions from ovariectomized rats.