Immunoassays employing substituted ammonium compounds other than neuromuscular blocking drugs to increase the detection of IgE antibodies to these drugs.

Subjects who experience life-threatening anaphylactic reactions to neuromuscular blocking drugs frequently have serum IgE antibodies that react with substituted ammonium groups on the drugs. Failure to detect drug-reactive antibodies may be due to the nature of the drug-solid support used for testing sera. With this in mind, solid phases of some selected compounds containing substituted ammonium groups, in particular triethylamine and morphine, were prepared and used to screen sera in an attempt to increase the frequency of detection of IgE antibodies complementary to tertiary and/or quaternary ammonium groups. For subjects who experienced an anaphylactic reaction to succinylcholine or gallamine, use of the supplementary assays increased the frequency of detection from 83 to 100%. For d-tubocurarine and alcuronium, detections increased from 92 to 100% and from 67 to 88%, respectively. Molecular models revealed a clear structural similarity between the conformations of the trialkylammonium groups on one face of the molecules of morphine and d-tubocurarine.