Adverse reactions to atracurium and alcuronium. A prospective surveillance study.

A multicentre prospective surveillance study was undertaken to compare the incidence and severity of adverse reactions attributed to atracurium and alcuronium. Clinical manifestations were used by the anaesthetist to diagnose an adverse reaction (a cutaneous reaction, a greater than 20% change in arterial pressure or heart rate, and bronchospasm). Of the 1956 patients receiving atracurium, 10.1% had adverse reactions compared with 17.9% of the 1425 patients receiving alcuronium (P less than 0.001). There were no longterm sequelae. The atracurium group had a markedly lower incidence of hypotension (3.4% v. 13.7%; P less than 0.0001), but a higher incidence of cutaneous reactions (4.6% v. 2.3%; P less than 0.005) which were not associated with other adverse reactions. There was a low incidence of bronchospasm in both groups (0.2% v. 0.1%).