We report on anaphylactoid reactions (urticaria, dyspnoea) after intra
muscular injection of diclofenac together with intravenous injection o
f morphine in a woman. Skin tests and intramuscular challenge with dic
lofenac showed no reaction. Skin tests with morphine were negative, bu
t intravenous challenge showed dose-dependent reactions. These results
indicate that the reactions were due to a non-immunological mechanism
in form of pharmacological intolerance.