Increased effects w/ halothane, isoflurane, enflurane, aminoglycosides, polymyxin, spectinomycin, tetracyclines, lincomycin, clindamycin, anti-arrhythmics, diuretics, Mg sulfate, ketamine, lithium salts, ganglion-blocking drugs. Increased sensitivity w/ β-blockers, anti-rheumatic drugs, trimetaphan, chlorpromazine, steroids, phenytoin. Prolonged & complex block w/ suxamethonium Cl. Shortened duration & diminished magnitude w/ anticholinesterases.