Canadian Journal of Anesthesia, Vol 24, 228-242, Copyright © 1977 by Canadian Anesthesiologists' Society

Dual Action of Pancuronium on Succinylcholine Block

¹ Department of Anesthesiology, Illinois Masonic Medical Center, University of Illinois, Abraham Lincoln School of Medicine, Chicago, Illinois
² Department of Anesthesiology, Michael Reese Medical Center, Chicago, Illinois
³ Biochemistry Laboratory, Veterans Administration Hospital, Hines, Illinois, U.S.A.

The effects of pretreatment with both sub-paralyzing and paralyzing doses of pancuronium and d-tubocurarine, on the onset and duration of succinylcholine-induced neuromuscular blockade were evaluated and compared in 225 patients. D-tubocurarine antagonized both onset and duration of succinylcholine block, while pancuronium produced a dual effect, antagonizing the onset and potentiating the duration of succinylcholine block. Pretreatment with d-tubocurarine (0.07 mg/kg, 0.3 mg/kg and 0.6 mg/kg) increased the time to onset of succinylcholine paralysis from 28 to 118 per cent, and decreased the duration from 16 to 37 per cent. Pancuronium (0.02 mg/kg, 0.04 mg/kg and 0.08 mg/kg) also antagonized the onset of succinylcholine paralysis with increases of 32 to 114 per cent, but potentiated its duration from 30 to 103 per cent compared with succinylcholine alone in the same patients. Although pancuronium markedly inhibited serum cholinesterase in vitro (I₅₀ = 5 x 10^-7 mol) there was only a 10 per cent inhibition of cholinesterase in vivo after pancuronium 0.08 mg/kg.