Toxic effects of drugs on erythrocytes.

The erythrocyte abnormality most often associated with the toxic effects of commonly used drugs is premature destruction. The mechanisms of erythrocyte destruction include: denaturation of unstable hemoglobins, oxidation of sulfhydril groups in hemoglobin and the erythrocyte membrane in the presence of glucose-6-phosphate dehydrogenase deficiency, direct effects on enzymes, cholesterol or phospholipids of the erythrocyte membrane, and various autoimmune reactions. Therapy includes stopping the drug and transfusions when anemia is severe. Splenectomy and steroids are rarely needed. A careful medical history and use of drugs only for good indications may avoid many of these reactions.