Pharmacologic intolerance reaction after intravenous injection of pethidine

We report on anaphylactoid reactions (urticae at the injection site and along the injection vein) after intravenous injections of pethidine in two patients. Skin tests with pethidine were negative, but intravenous challenge showed urticae. These results indicate that the reactions were due to a non-immunological mechanism resembling pharmacological intolerance. Retrospective analysis revealed a 5.6% incidence of pharmacological intolerance reactions to intravenous pethidine in 519 patients.