Ostergaard_1995_Acta.Anaesthesiol.Scand_39_1016

During thiopentone-fentanyl-nitrous oxide anaesthesia and using a cumulative design, we studied the dose-response relationship of mivacurium in 8 patients: 7 patients phenotypically homozygous for the atypical plasma cholinesterase gene and 1 patient homozygous for the silent gene. The estimated mean ED50 and ED95 were 15 and 20 micrograms.kg.bw-1 in patients homozygous for the atypical gene, and 13 and 16 micrograms.kg.bw-1 in the patient homozygous for the silent gene, respectively. The results indicate that mivacurium is 4-5 times more potent in patients homozygous for the atypical or the silent gene than in patients with normal plasma cholinesterase activity and phenotype.