Haema 2010; 1(2): 137-145
Athanasios Galanopoulos
Haematology Department, “G. Gennimatas” General Hospital, Athens, Greece
Abstract
Drug-induced immune thrombocytopenia (DITP) can be caused by perhaps hundreds of medications. Thrombocytopenia may be caused by many other causes and therefore, the diagnosis of DITP can be easily overlooked and misdiagnosed as autoimmune thrombocytopenia (AIT), thrombocytopenia attributed to bacteremia and sepsis, the effect of coronary-artery bypass surgery, or some other underlying condition. Although many cases of DITP are mild, some are characterized by life-threatening symptoms. The pathogenesis of DITP is complex and at least six different mechanisms by which drug-induced antibodies can promote platelet destruction have been proposed. In many cases, it is possible to identify the antibodies which react with platelets in the presence of the sensitizing drug, but it is not always technically feasible, so the decision to discontinue the suspected medication in the patient should be made on clinical grounds. Although identification of a platelet-reactive drug-dependent antibody (DDAb) is not useful in acute management, antibody identification can help to implicate a specific drug as the cause of thrombocytopenia and prevent future exposure to this drug. Drug discontinuation usually results in recovery of thrombocytopenia. In rare cases, thrombocytopenia and bleeding symptoms persist for several weeks. Such patients have been treated with corticosteroids, intravenous IgG and plasmapheresis with possible, but not proven, benefit.