Prolonged apnea may occur in patients with a genetically 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%.