Interaction between atracurium and drugs used in anaesthesia.

The effects of various drugs used during anaesthesia on the neuromuscular blocking activity of atracurium have been studied in anaesthetized cats. Clinically effective doses of diazepam, morphine, pentazocine, pethidine, ketamine, Althesin, methohexitone, Septrin, lignocaine, propranolol, calcium chloride or azathioprine did not significantly alter the neuromuscular blocking action of atracurium. Recovery from atracurium was not prolonged during an infusion of hexamethonium or sodium nitroprusside, indicating that, despite the severe hypotension, the inactivation of atracurium was unimpaired. Similar to that of other competitive neuromuscular blocking agents, the action of atracurium was enhanced by tubocurarine, halothane, gentamycin, neomycin and polymixin and was antagonized by adrenaline and transiently antagonized by suxamethonium. However, pretreatment with suxamethonium did not affect the subsequent block by atracurium.