Recurarisation following a suxamethonium-alcuronium sequence in patients with atypical cholinesterase

Alcuronium 10 mg was administered to maintain muscle relaxation in two patients before recovery from suxamethonium neuromuscular blockade to facilitate tracheal intubation. This sequence resulted in a markedly prolonged block which could not be antagonised adequately by neostigmine 0.05 mg/kg; initial antagonism was followed rapidly by prolonged recurarisation. Estimation of plasma cholinesterase activity revealed that the two patients were homozygous for the atypical and silent genes. respectively.