Effects of diazepam on succinylcholine-induced myalgia, potassium increase, creatine phosphokinase elevation, and relaxation.

Diazepam in a dose of 0.05 mg/kg was studied to determine its effect on a subsequently administered dose of 1 mg/kg of succinylcholine. This dose of diazepam prior to succinylcholine (1) significantly diminished the incidence of postoperative muscle pain; (2) decreased the usual increase in serum potassium; (3) did not prevent the rise in creatine phosphokinase; (4) reduced the incidence of muscle fasciculation; and (5) did not affect the magnitude or duration of the succinylcholine neuromuscular block. It was concluded that diazepam had several advantages over d-tubocurarine in the prevention of succinylcholine-induced muscle pain.