Drug-induced immune hemolytic anemia (Direct Antiglobulin Test positive).

Drug-induced immune hemolytic anemia occurs rarely (1 in 1 million population).1 It is an uncommon finding characterized by a sudden decrease in hemoglobin after treatment with the putative drug. To date, about 100 drugs have been implicated in causing a positive Direct Antiglobulin Test (DAT) and/or hemolytic anemia. The most common drugs associated with this, are penicillin and its derivatives, cephalosporins (cefotetan, ceftriaxone etc.), methyldopa, β-lactamase inhibitors and quinidine. Drug antibodies fall into two types: drug-independent (autoantibodies) and drug-dependent (“penicillin type” or “immune complex type”). Some drugs cause non-immunologic protein adsorption onto drug-treated red blood cells (RBCs).1–3 All these mechanism are associated with positive DAT which may lead to hemolytic anemia.