Prolongd apnea may occur in patients with a genertically determined abnormal variant of cholinesterase following intravenous administration of

Both succinylcholine and mivacurium are completely and rapidly eliminated by plasma cholinesterase. Other nondepolarizing neuromuscular blockers, such as tu­bocurarine, pancuronium, and atracurium, are elimi­nated by renal or hepatic mechanisms or by spontane­ous hydrolysis (atracurium). Patients with genetically determined atypical cholinesterase may be detected by measuring the inhibition of cholinesterase by dibu­caine, a local anesthetic. Dibucaine inhibits the normal enzyme about 80%, but the abnormal variant is inhib­ited only 20%.