Morphine-induced immune thrombocytopenia

Sudden thrombocytopenia that was temporally related to the administration of morphine sulfate developed in a 23-year-old woman. A morphine-dependent platelet antibody was found in her serum by chromic chloride Cr 51 platelet lysis. The antibody was complement dependent, present in the IgG immunoglobulin fraction, and its drug-dependent platelet lytic activity was demonstrable with several narcotic analgesics in addition to morphine. The antibody activity declined over an eight-month period following recovery from thrombocytopenia. To our knowledge, morphine-induced immune thrombocytopenia has not previously been described.