A nurse is reviewing the laboratory findings of a client who is taking erythropoietin. Which of the following results indicates the medication is effective?

A. Decreased white blood cells: Erythropoietin specifically stimulates red blood cell production in the bone marrow. White blood cell counts are not directly affected by this medication, so a decrease would not indicate effectiveness. B. Increased calcium: Calcium levels are unrelated to erythropoietin therapy. Changes in calcium do not reflect the medication’s ability to stimulate erythropoiesis. C. Increased hemoglobin: Erythropoietin promotes red blood cell production, which increases hemoglobin and hematocrit levels. An elevation in hemoglobin indicates the medication is effectively stimulating erythropoiesis. D. Decreased BUN: Blood urea nitrogen reflects kidney function and protein metabolism. While erythropoietin is often used in clients with chronic kidney disease, a decrease in BUN is not a direct measure of the drug’s effectiveness.