- Triggers: anti-inflammatory medications, penicillins, and cephalosporins
- Pathogenesis
- Drug coats erythrocytes → IgG binding → splenic destruction of RBCs (extravascular hemolysis)
- Drug triggers immune complexes → complement-mediated destruction of RBCs (intravascular hemolysis)
- Manifestations
- Sudden onset (within hours of exposure)
- Anemia: fatigue, pallor, dyspnea
- Hemolysis: jaundice, dark urine, abdomen/back pain
- ↑ Reticulocytes, indirect bilirubin & LDH
- ↓ Haptoglobin
- Spherocytes on peripheral blood smear
- +Direct Coombs test (anti-IgG, anti-C3)
- Treatment
- Discontinue offending drug