CLINICAL PHARMACOLOGY OF ATRACURIUM GIVEN IN HIGH DOSE

The safety and efficacy of atracurium 0.8 mg kg^–1 wasdetermined in healthy patients with particular attention tothe speed of onset of blockade, and to changes in haemodynamicvariables. Atracurium 0.8 mg kg^–1 had a shorter onsettime than atracurium 0.5 mg kg^–1, and satisfactory intubatingconditions were achieved earlier. "Priming" produced no significantimprovement in onset time or intubating conditions. Onset timeswere significantly shorter with nitrous oxide-opioid anaesthesiathan following thiopentone alone. Although a 0.8-mg kg^–1bolus resulted in a significant reduction in mean arterial pressureto 75% of control and was associated with a significant increasein plasma histamine concentrations, this response could be preventedby injecting the drug over 75 s. "Priming" or a 30-s injectionproduced no haemodynamic protection. The protection achievedby pretreatment with anti-histamines was incomplete: mean arterialpressure decreased to 83% of control. Presented at the International Anaesthesia Research SocietyCongress, Las Vegas, U.S.A. on March 19, 1986.