Chlorpromazine and allied substances.

Promethazine (phenergan) has two methyl groups, which in these derivatives are associated with strong antihistaminic power, while chlorpromazine is a propylamine phenothiazine, which has more marked central nervous system effects but only one-hundredth of the antihistamine potency of promezathine. The Department of Pharmacology at Oxford has pointed out (Burns, 1948; Burns and Dutta, 1948; Dews and Graham, 1946) that atropine, pethidine, procaine, quinidine and also the antihistamine drugs share many properties-in common; spasmolytic, analgesic, 'quinidine-like,' hypothermic and antihistamine effects are all seen. These multiple effects were expected and later Chlorpromazine Hydrochloride (4560 R.P.) (Largactil)