The nurse administers epoetin alfa to a client who has chronic kidney disease (CKD). Which laboratory test value would the nurse monitor to determine this drug's effectiveness?

Rationale: A. Hemoglobin is the primary laboratory value used to determine the effectiveness of epoetin alfa therapy. Epoetin alfa stimulates the bone marrow to produce red blood cells (RBCs), thereby increasing hemoglobin and hematocrit levels. Monitoring hemoglobin helps evaluate the medication’s success in correcting anemia secondary to chronic kidney disease (CKD). The therapeutic goal is usually a hemoglobin level of 10–11 g/dL; levels higher than this increase the risk of hypertension and thromboembolic events. B. Renin is an enzyme involved in the renin-angiotensin-aldosterone system and reflects renal perfusion and blood pressure regulation, not the effect of epoetin alfa. C. Sodium levels are related to fluid balance and kidney function but are not influenced by epoetin alfa therapy. D. Potassium levels can fluctuate with CKD or dialysis treatment, but epoetin alfa does not directly affect potassium concentration.