Increased effect w/ enflurane, isoflurane, halothane, ketamine, other non-depolarising neuromuscular blockers, aminoglycosides, polymyxins, spectinomycin, tetracyclines, lincomycin, clindamycin, anti-arrhythmics, diuretics, Mg & lithium salts, ganglion-blocking drugs. Increased sensitivity w/ β-blockers, antirheumatic drugs, trimetaphan, chlorpromazine, steroids, phenytoin. Prolonged effect w/ suxamethonium. Decreased effect by phenytoin or carbamazepine. Shortened duration & diminished magnitude w/ anticholinesterases.