A patient with chronic renal failure is receiving Epoetin Alfa. Which laboratory result would indicate a therapeutic effect of the medication?

1. A

   Hematocrit 32%

2. B

   Platelet count of 400,000 cells /mm³

3. C

   WBC count of 6000 cells /mm³

4. D

   BUN of 15 mg/dl

Appeared in: JODHPUR AIIMS SNO-2018

Explanation

• Epoetin alfa is an erythropoiesis-stimulating agent (ESA) used to treat anemia, particularly in patients with chronic kidney disease who cannot produce enough natural erythropoietin.
• The primary therapeutic goal of Epoetin alfa is to increase the production of red blood cells (erythrocytes).
• An increase in hematocrit (the percentage of blood volume occupied by red blood cells) is the direct measure of the drug's effectiveness.
• For patients with chronic renal failure, the target hematocrit level is typically between 30% and 36% (or a hemoglobin of 10-11 g/dL) to balance efficacy with safety.
• A hematocrit of 32% falls squarely within this target therapeutic range, indicating the medication is working as intended.

Why Other Options Were Wrong

• Option B: The platelet count measures the number of thrombocytes, which are involved in blood clotting. Epoetin alfa's mechanism of action is specific to stimulating red blood cell progenitors and does not directly affect platelet production.
• Option C: The White Blood Cell (WBC) count reflects the body's immune status and response to infection or inflammation. Epoetin alfa does not target the production of leukocytes (WBCs).
• Option D: Blood Urea Nitrogen (BUN) is a waste product filtered by the kidneys. While it is a crucial indicator of renal function, it does not measure the bone marrow's response to Epoetin alfa.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Therapeutic Drug Monitoring to guide bedside assessment, documentation, and the next nursing action.
• Nurses administering Epoetin alfa must monitor blood pressure before and during therapy, as hypertension is a common and serious adverse effect due to the increased blood viscosity from higher red blood cell counts.
• It is critical to monitor hemoglobin and hematocrit levels to ensure they do not rise too quickly or exceed the target range (Hgb above 11 g/dL for renal patients), as this significantly increases the risk of thrombosis, myocardial infarction, and stroke.
• Patient education should include the importance of adhering to lab appointments, reporting signs of hypertension (headache, blurred vision), and understanding that iron supplements are often required for Epoetin alfa to be effective.

How to Approach the Question

• First, identify the drug mentioned: Epoetin Alfa. Recall or look up its class and mechanism of action. It is an erythropoiesis-stimulating agent.
• Next, understand the patient's condition: chronic renal failure. This condition causes a deficiency in natural erythropoietin, leading to anemia.
• Connect the drug to the condition: Epoetin Alfa is given to treat the anemia caused by renal failure.
• Determine how the drug's therapeutic effect is measured. Since it stimulates red blood cell (RBC) production, the answer must be a lab value related to RBCs.
• Evaluate the options: Hematocrit is a direct measure of RBC volume. Platelets, WBCs, and BUN are unrelated to the primary effect of Epoetin alfa.
• Select the option that shows a successful, but not excessive, response. A hematocrit of 32% is within the accepted therapeutic range for this patient population.

Concept Tested & Keywords

• Concept Tested: Therapeutic Drug Monitoring
• Stem keywords: chronic renal failure, Epoetin Alfa, laboratory result, therapeutic effect
• Lead-in keywords: Which
• Clinical cues: Patient with chronic renal failure, indicating impaired erythropoietin production.
• Clinical cues: Medication is Epoetin Alfa, an erythropoiesis-stimulating agent.

Question ID

qYiFHMskA10sI_pjJCo3r

Copy ID

Reference Book

E6 Pharmacology Nursing Lilley 11e Part 3 p. 218-220

E6 Pharmacology Katzung 16e p. 938-940