MORPHINE AND HISTAMINE RELEASE

Abstract
A wide range of drugs exert analeptic action in dogs treated with morphine; cyclizine, diphenhydramine, chlorcyclizine, Avil, tripelennamine and succinic acid. Benactyzine and Pacatal are without effect. Histamine and an antihistaminase (isoniazid) exert some alerting action in a morphine-treated dog. Morphine induces the signs of histamine release in some dogs. Histamine itself reproduces some of the side effects of morphine. Histamine-treated dogs appear to be analgesic. Rabbits and dogs, behaved similary but cats were different and variable when given antihistamine drugs after morphine. Some of the side actions of morphine are mediated by histamine release.