In general, antibiotics as a class potentiate both depolarizing muscular blocking drugs and nondepolarizing neuromuscular blocking drugs to varying degrees. Aminoglycosides have been reported to have a magnesium like effect on the neuromuscular junction. Amphotericin induced hypokalemia has been observed to potentiate. Lincosamides (clindamycin, lincomycin) principal action is direct effect on muscle. Tetracycline administration chelates calcium. Metronidazole can potentiate the effects of NDMBs.
Other drug classes that interact with muscle relaxants include anticonvulsants, various antiarrhythmics, and inhaled anesthetics. The acute administration of anticonvulsants typically decreases the sensitivity to NDMD whereas patients chronically taking anticonvulsants typically require higher doses of nondepolarizing agents. Quinidine can potentiate the effects of depolarizing and non-depolarizing agents. Volatile anesthetics produce dose dependent potentiation of NDMBs. The degree of muscle relaxant potentiation is dependent upon tissue saturation of the inhalational agent.
Defined by: Richard Murray, MD