Pharmacological Aspects of Concurrent Administration of Furosemide and Skeletal Muscle Relaxants

Abstract

The pharmacological aspects of concurrent administration of furosemide and the skeletal muscle relaxants, d-tubocurarine, succinylcholine, and chlordiazepoxide, were investigated with respect to the effects on diuresis and skeletal muscle relaxation in female albino rats. Administration of d-tubocurarine and chlordiazepoxide concurrently with furosemide produced no significant effects on furosemide-induced diuresis. Succinylcholine, when administered concurrently with furosemide, caused a decrease in the volume of urine excreted; other parameters of renal function were not affected. The skeletal muscle relaxant properties of d-tubocurarine, succinylcholine, and chlordiazepoxide were investigated upon concurrent administration of the muscle relaxants with furosemide by an in vivo study and an in situ study. The skeletal muscle relaxant action of succinylcholine was significantly potentiated by pretreatment of the animals with furosemide, both in the exercise wheel study and in the diaphragm-phrenic nerve preparation. A tendency toward an antagonism between d-tubocurarine and furosemide was observed on skeletal muscle relaxation both in vivo and in situ. The effect of d-tubocurarine on blood pressure was also antagonized by treatment of the animal with furosemide. Preliminary spectrophotometric evidence suggests that a complex between furosemide and d-tubocurarine exists, which may possibly explain an antagonism between the two drugs.