Case report: hemolytic anemia produced by tolmetin

Tolmetin, a nonsteroidal anti-inflammatory drug, was found to be the etiologic agent in a case of drug-induced hemolytic anemia. A 35-year-old female who had ingested tolmetin sporadically in the past took two doses that resulted in acute hemolysis. Two days after taking the second dose, she had a hemoglobin of 7.0 g/dL, increased serum lactate dehydrogenase, reticulocytosis, and indirect reacting hyperbilirubinemia. The direct antiglobulin test was weakly positive with anti-lgG and anticomplement reagents. The patient's serum was nonreactive with reagent red cells in the absence of tolmetin, but addition of tolmetin to the serum resulted in strong agglutination of all reagent red cells tested. Serologic evaluation of this patient’s serum indicated that tolmetin caused hemolysis by an immune complex mechanism. Hemolysis subsided and anemia improved spontaneously. Immunohematology 1992;8:17-18.