Histamine liberation in surgical patients following administration of neuromuscular blocking drugs

The effects of five commonly used neuromuscular blocking drugs on histamine liberation were studied in 105 surgical patients. After standard premedication with pethidine and atropine the patients were anaesthetized with thiopental sodium. d-Tubocurarine and succinylcholine caused significant histamine liberation while alcuronium, gallamine, and pancuronium did not appear to exert this effect. d-Tubocurarine seems to liberate histamine by acting directly on the blood cells thus causing a decrease of histamine in the whole blood and an elevation in plasma. On the other hand, the succinylcholine-induced liberation of histamine may be mediated by muscular fasciculations as it causes an elevation of histamine in whole blood and in plasma. No correlation was found between histamine liberation and blood pressure changes. Erythematous skin reactions were the only clinical sign of histamine liberation caused by intravenous administration of the neuromuscular blocking drugs.