Case report: hemolytic anemia produced by tolmetin

Area of Science:

• Pharmacology
• Hematology
• Immunology

Background:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) can rarely cause adverse hematologic reactions.
• Drug-induced hemolytic anemia (DIHA) is a serious condition requiring prompt diagnosis and management.

Purpose of the Study:

• To identify the etiologic agent in a case of drug-induced hemolytic anemia.
• To elucidate the immunoserologic mechanism of tolmetin-induced hemolysis.

Main Methods:

• Case report of a 35-year-old female presenting with acute hemolysis after tolmetin ingestion.
• Laboratory investigations including complete blood count, liver function tests, reticulocyte count, and direct antiglobulin test (DAT).
• In vitro testing of patient's serum with tolmetin and reagent red blood cells.

Main Results:

• The patient developed severe anemia (hemoglobin 7.0 g/dL) with signs of hemolysis.
• Direct antiglobulin test was weakly positive for IgG and complement.
• Patient's serum demonstrated tolmetin-dependent agglutination of red blood cells, indicating an immune complex mechanism.

Conclusions:

• Tolmetin was identified as the causative agent of drug-induced hemolytic anemia in this patient.
• The mechanism of hemolysis involved the formation of immune complexes with tolmetin.
• Spontaneous resolution of hemolysis and anemia occurred upon cessation of tolmetin.