Morphine, historically chief among the opioids , is widely used as an analgesic in various clinical situations (postoperative period, cancer).
General: anaphylactic shock.
Intradermal skin-tests: positive 1/100 000 (solution of 10 mg/ ml)
Specific IgE (RIA morphine-sepharose) positive in a patient.
Nonspecific histamine release.
IgE-mediated hypersensitivity: the morphine allergenic determinant comprises the cyclohexenyl ring, with a hydroxyl group at C6 and a methyl substituent attached to the N-atom.
Cross-reactivity with codeine and other opioids may occur.