Muscle relaxation action may be reduced or potentiated depending on the sequence of co-administration w/ depolarizing muscle relaxants (eg, suxamethonium) or other non-depolarizing muscle relaxants. Potentiated muscle relaxation action w/ inhalation anaesth (eg, isoflurane, sevoflurane, halothane ether), lithium salt prep; K excretion type diuretic (eg, furosemide, thiazides); MAOI, protamines, β-blocker, metronidazole, Ca antagonist, cimetidine, bupivacaine; aminoglycosides, lincosamides, polypeptides, acylamino-penicillins, Mg salt prep, quinidine, quinine; IV administration of phenytoin during surgery; lidocaine. Reduced muscle relaxation action w/ CaCl
2 or KCl formulations; PI (eg, gabexate, ulinastatin); prolonged pre-administration of adrenocortical hormone agent, or antiepileptic agent (eg, carbamazepine, phenytoin). Accelerated onset of lidocaine action.