Detection of thiopentone-reactive IgE antibodies following anaphylactoid reactions during anaesthesia.

A radioimmunoassay was developed to detect IgE antibodies to the anaesthetic induction agent thiopentone. Significant levels of thiopentone-reactive IgE antibodies were found in the sera of two patients who had experienced life-threatening anaphylactoid reactions following administration of the drug. Inhibition experiments revealed that cross-reactivity occurs between the drug-reactive IgE antibodies and four barbiturate analogues pentobarbitone, phenobarbitone, barbitone and methohexital. The assay should supplement skin testing for the detection of patients with potentially lethal sensitivity to thiopentone.