Interactions of serotonin with neuromuscular blocking agents

Abstract

Serotonin has been shown to reverse blockade induced by the nondepolarizing agents and hemicholinium and to potentiate blockade produced by the depolarizers. It is more effective at low frequencies of stimulation. The drug augments the twitch potentiations produced by small doses of decamethonium and neostigmine. It has no effect on exogenously applied acetylcholine. The agent increases the vascular resistance but this is not a prerequisite to its myoneural actions. Rubidium efflux from vascular strips, which is a measure of potassium permeability, is not affected by the chemical. At a dose of 10 μg/ml there is no anticurare action in vitro. All of the neuromuscular actions of serotonin can be prevented by administration of methysergide. It is postulated that the agent might act presynaptically to release acetylcholine by the interaction with serotonin D-receptors.