Anaphylactoid reactions muscle relaxants

Anaphylactic reactions result from the interaction of antigens with specific IgE antibodies, which have been formed by previous exposure to the antigen. Anaphylactoid reactions are clinically indistinguishable from anaphylaxis but do not result from prior exposure to a triggering agent and do not involve IgE. Intravenous anaesthetics and muscle relaxants can cause anaphylactic or anaphylactoid reactions and, rarely, they are fatal. Muscle relaxants are responsible for 70% of anaphylactic reactions during anaesthesia and suxamethonium accormts for almost half of these. 

Histamine release and anaphylactoid reactions occur with alcuronium (10-12). The precise incidence is not clear. Erythema is said to occur much less frequently than after D-tubocurarine (3). A retrospective study in Australia (13) showed that 37% of serious anaphylactoid reactions reported there were associated with alcuronium alcuronium, however, at that time accounted for almost 50% of the total muscle relaxant consumption in Australia, and if this is taken into account the likelihood of a serious reaction is less than with D-tubocurarine, as others have also concluded (14). Chnical features reported range from erythema to severe hypotension and tachycardia (15) and bronchospasm (16,17). In a large prospective surveillance study (SEDA-15,125) (SED-12,473) involving over 1400 patients given alcuronium (initial dose 0.25 + 0.09 mg/kg), there were adverse reactions in almost 18% of the patients, with moderate hypotension (20-50% fall) in 13%, severe hypotension in 0.8%, and bronchospasm in 0.1%. 

Fisher MM, Munro I. Life-threatening anaphylactoid reactions to muscle relaxants. Anesth Analg 1983 62(6) 559-64. 

Baldo BA, Harle DG, Fisher MM. In vitro diagnosis and studies on the mechanism(s) of anaphylactoid reactions to muscle relaxant drugs. Ann Fr Anesth Reanim 1985 4(2) 139 5. 

Thacker MA, Davis FM. Subsequent general anaesthesia in patients with a history of previous anaphylactoid/ana-phylactic reaction to muscle relaxant. Anaesth Intensive Care 1999 27(2) 190-3. 

Some authors stress the fact that vancomycin can interact with anesthetic drugs, particularly muscle relaxants. In the reported cases anaphylactoid reactions were seen, with intense erythema and marked permeability changes (125). 

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