Increased effect w/ halogenated volatile anesth; high doses (thiopental, methohexital, ketamine, fentanyl, γ-hydroxybutyrate, etomidate & propofol); other non-depolarizing neuromuscular blocking agents, suxamethonium. Prolonged duration of neuromuscular block or myopathy w/ corticosteroids. Antibiotics (eg, aminoglycosides, lincosamides, polypeptide antibiotics, acylamino-penicillin, tetracyclines, high doses of metronidazole; diuretics, thiamine, MAOIs, quinidine & its isomer quinine, protamine, adrenergic blockers, Mg & lithium salts, Ca channel blockers, local anesth. Decreased effect w/ neostigmine, edrophonium, pyridostigmine, aminopyridine derivatives, corticosteroids, phenytoin, carbamazepine, noradrenaline, azathioprine, theophylline, CaCl, KCl, PIs. May produce attenuation or potentiate neuromuscular block w/ non-depolarizing neuromuscular blockers & suxamethonium. More instant effect of lidocaine.