Histamine-release haemodynamic changes produced by rocuronium, vecuronium, mivacurium, atracurium and tubocurarine

We have examined the effects of different benzyl-isoquinolinium andsteroidal neuromuscular blocking compounds on plasma concentrations ofhistamine, heart rate and arterial pressure in surgical patients. A single,rapid (5-s) bolus of mivacurium 0.2 mg kg-1, atracurium 0.6 mg kg-1,tubocurarine 0.5 mg kg-1, vecuronium 0.1 mg kg-1 or rocuronium 0.6 mg kg-1was administered to 75 patients (n = 15 in each group). Anaesthesia wasinduced with thiopentone 6 mg kg-1 i.v. and maintained with isoflurane and70% nitrous oxide in oxygen. Venous blood samples were obtained beforeinduction, 1 min after thiopentone and 1, 3 and 5 min after administrationof the neuromuscular blocking drug. Mivacurium, atracurium and tubocurarinecaused 370%, 234% and 252% increases in plasma histamine concentrations at1 min, respectively. Corresponding values at 3 min were 223%, 148% and157%, respectively. These changes were significant (P < 0.01) at 1 and 3min. In contrast, the rocuronium and vecuronium groups had no significantchanges in either plasma histamine concentrations or haemodynamicvariables.