Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002878 (hemolytic anemia)
 7,530 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ingestion of drugs can cause patients or blood donors to have a positive direct and sometimes indirect antiglobulin test. The most common cause of these positive reactions and immune hemolytic anemia due to drugs is the formation of red cell autoantibodies. These autoantibodies will react with the patient's own red cells and usually most other normal red cells in vitro without the drug being present. The prototype drug causing this type of reaction is alpha methyldopa (Aldomet). Other drugs cause positive antiglobulin tests by three different mechanisms, the drug antibodies reacting with red cells in vitro only in the presence of the drug. The first of these mechanisms causes positive reactions because the drug binds firmly to the red cell membrane, and antibody against the drug will combine with the drug on the membrane leading to IgG-sensitized red cells. The prototype drug for this mechanism is penicillin. The second mechanism involves chemical modification of the red cell membrane by the drug so that it takes up many proteins nonspecifically; the cephalosporins are the only group of drugs known to react in this fashion. The final mechanism involves the formation of an immune complex by the drug and its specific antibody. This immune complex will attach to cell membranes, usually activating complement in the process. Examples of drugs thought to operate by this mechanism are phenacetin, quinine, and quinidine. Some individuals have antibodies present in their serum that will react with chemical added to commercial blood bank reagents. Examples of these are antibodies to dyes added to ABO typing sera, antibodies to sodium caprylate in bovine albumin, and antibodies to chemicals added to red cell diluents, e.g., chloramphenicol, neomycin, and hydrocortisone. If these antibodies are present they can create problems in pretransfusion testing; in particular, they can present anomalies in ABO, Rh grouping, and antibody detection.
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PMID:Problems in pre-transfusion tests related to drugs and chemicals. 77 71

Methyldopa is an antihypertensive medication which is available generically and under the trade name Aldomet that is widely prescribed in the adult population and infrequently used in children. Methyldopa causes an autoimmune hemolytic anemia in a small percentage of patients who take the drug. We report a case of methyldopa-induced hemolytic anemia in a 15-year-old boy who presented to the emergency department with near-syncope. The boy had been treated with intravenous methyldopa during a trauma admission seven weeks prior to presentation. Evaluation revealed a hemoglobin of three grams, 3+ Coombs' test with polyspecific anti-human globulin and monospecific IgG reagents, and a warm reacting autoantibody. Transfusion and corticosteroid therapy resulted in a complete recovery of the patient. Emergency physicians treating children must be aware of this syndrome in order to diagnose and treat it correctly. A brief review of autoimmune and drug-induced hemolytic anemias is provided.
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PMID:Methyldopa-induced hemolytic anemia in a 15 year old presenting as near-syncope. 232 Apr 85

Acute near-fatal intravascular hemolysis and renal failure developed in a patient after he had ingested 15 to 20 tablets of both methyldopa (Aldomet) nd hydrochlorothiazide (HydroDiuril). Serologic test results were inconsistent with those associated with methyldopa-induced hemolytic anemia and suggested that hemolysis was caused by hydrochlorothiazide antibodies reacting by an immune complex mechanism.
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PMID:Acute immune intravascular hemolysis due to hydrochlorothiazide. 725 54