New neuromuscular blocking drugs

Summary Four new non-depolarizing drugs offer advantages in different clinical situations. Pipecuronium and doxacurium are long-acting compounds with a relatively slow onset and a variable duration of action. Their main advantage is a lack of cardiovascular side-effects. Their use is likely to be confined to prolonged surgical procedures. Mivacurium has an onset of action similar to atracurium and vecuronium and a duration of action midway between these drugs and suxamethonium. It is metabolized by plasma cholinesterase and may not require to be routinely antagonized by anticholinesterases. Rocuronium (Org 9426) has a duration of action similar to atracurium and vecuronium but a more rapid onset of action. Whether it can replace suxamethonium in the rapid sequence induction requires further clinical assessment, but it would appear to be the drug of choice for rapid intubation where suxamethonium is contraindicated.