A positive Coombs’ test and hemolytic anemia may follow the administration of which antihypertensive drug?
- Methyldopa
- Clonidine
- Guanabenz
- Prazosin
- Captopril
Many drugs can cause an immunohemolytic anemia. Methyldopa may cause a positive Coombs’ test in as many as 20% of patients, along with hemolytic anemia. Other drugs with similar actions on red blood cells are penicillins, quinidine, procainamide, and sulfonamides. These form a stable or unstable hapten on the red cell surface, which induces an immune reaction [immunoglobulin G (IgG) antibodies] and leads to dissolution of the membrane.