The action of succinyl choline chloride and its interaction with chlorpro mazine was investigated by simultaneous recording of the indirectly elicited muscle twitches of the Tibialis anterior and the upper lip muscles of the anaesthetised dogs. The onset time, duration of action and reco very index were studied. The prior administration of chlorpromazine resulted in, prolongation of the neuromuscular blocking action of succinyl choline and reduced its relaxant dose.
It could be concluded that the effect of succinyl choline in anaesthetised dogs varied according to the premedication.