Potentiation of Amipaque epileptogenic activity by neuroleptics.

Experiments conducted on rabbits confirmed that chlorpromazine potentiates the weak epileptogenic action of Amipaque (metrizamide). Chlorpromazine withdrawal for a period of 48 h suppresses this potentiating effect in the rabbit. Neuroleptic drugs should therefore be avoided in patients examined with Amipaque. In patients under chronic treatment, neuroleptics ought to be discontinued at least 48 h before examination with Amipaque. With the doses and methods used in the present study, diazepam was not as effective as phenobarbital in preventing epilepsy produced by Amipaque. When premidication is needed or when convulsions occur after Amipaque examinations, combined diazepam and phenobarbital therapy ought to be instituted in order to achieve the best control of epileptic reactions.