Precision in Practice: Strategic Procrit-to-Aranesp Conversion Resolves Adherence Challenges in Hemodialysis

Patient Information

Patient: 68-year-old male, R.G.
Primary Diagnosis: End-stage renal disease secondary to diabetic nephropathy
Dialysis Status: Maintenance hemodialysis, three times weekly for 4 years
Relevant Comorbidities: Type 2 diabetes (15-year duration), hypertension, coronary artery disease with prior CABG, peripheral vascular disease

Clinical Background

R.G. has been maintained on thrice-weekly in-center hemodialysis for four years. His anemia has been managed with Procrit (epoetin alfa) 10,000 units administered three times weekly at the end of each dialysis session (total weekly dose: 30,000 units). He was receiving IV iron sucrose 100 mg weekly with maintenance ferritin levels between 500-700 ng/mL and transferrin saturation (TSAT) 25-30%.

Clinical Presentation

During a routine nephrology clinic visit, R.G. complained of increased fatigue between dialysis sessions. Lab work revealed:

Hemoglobin: 9.8 g/dL (target range 10-11 g/dL)
Serum ferritin: 620 ng/mL
TSAT: 28%
Kt/V: 1.4 (adequate dialysis)
Albumin: 3.6 g/dL
PTH: 425 pg/mL (moderately elevated)
No evidence of bleeding or hemolysis

A review of his hemodialysis records showed inconsistent Procrit administration, with approximately 15% of doses missed over the previous three months due to the patient occasionally leaving dialysis sessions early before the medication could be administered.

Clinical Decision

The nephrologist decided to convert R.G. from Procrit to Aranesp for two primary reasons:

The less frequent dosing schedule would improve adherence
The longer half-life would provide more stable hemoglobin levels between dialysis sessions

Conversion Process

Baseline ESA Therapy: Procrit 10,000 units three times weekly (30,000 units/week)Conversion Calculation:
Based on the conversion table, an epoetin alfa dose of 30,000 units/week corresponds to the 18,000-33,999 units/week range, indicating a recommended Aranesp starting dose of 60 mcg/week.The nephrologist documented:

"Convert from Procrit 10,000 units TIW (30,000 units/week) to Aranesp 60 mcg IV once weekly to be administered at the end of the first dialysis session each week. This conversion uses an approximate ratio of 500:1 (30,000 units ÷ 60 mcg), which is more conservative than the standard 200:1 ratio to account for the patient's comorbidities and avoid potential hemoglobin overshoot."

Monitoring Plan

Weekly hemoglobin levels for the first month
CBC with reticulocyte count every two weeks
Iron studies (ferritin and TSAT) monthly
Clinical assessment of symptoms at each dialysis session
Continue IV iron supplementation at current dose

Clinical Course

Week 1: Hemoglobin 9.7 g/dL, patient reports no significant change in symptoms.

Week 2: Hemoglobin 9.9 g/dL, patient notes slight improvement in energy level.

Week 4: Hemoglobin 10.3 g/dL, reticulocyte count 2.1%, improved energy level reported.

Week 8: Hemoglobin 10.8 g/dL, reticulocyte count 1.8%, ferritin 580 ng/mL, TSAT 26%. Patient reports significant improvement in fatigue and exercise tolerance.

Week 12: Hemoglobin 11.2 g/dL, which slightly exceeded the target range. The nephrologist reduced the dose to Aranesp 50 mcg once weekly.Week 16: Hemoglobin stabilized at 10.5 g/dL.

Long-term Outcome

After six months on Aranesp, the patient maintained hemoglobin levels between 10.2-10.7 g/dL with the 50 mcg weekly dose. The dialysis unit reported 100% adherence to the ESA regimen. The patient's quality of life improved with less interdialytic fatigue, better exercise tolerance, and fewer ESA-related side effects.The patient's medication administration record confirmed no missed doses, and the simplified regimen allowed the nursing staff to administer the medication consistently each week even when the patient occasionally needed to leave dialysis early.

Discussion Points

Conversion Ratio Selection: The nephrologist chose a more conservative conversion ratio (500:1 rather than 200:1) recognizing the patient's comorbidities and history of cardiovascular disease, which warranted careful avoidance of rapid hemoglobin increases.
Pharmacokinetic Advantage: The extended half-life of darbepoetin alfa (approximately 3 times longer than epoetin alfa) provided more stable hemoglobin levels between dialysis sessions, addressing the patient's primary complaint of interdialytic fatigue.
Administration Convenience: Switching from a thrice-weekly to a once-weekly regimen significantly improved medication adherence, as evidenced by the elimination of missed doses.
Dose Optimization: The initial Aranesp dose required only one adjustment (from 60 to 50 mcg weekly) to achieve stable hemoglobin levels within the target range, demonstrating the accuracy of the conversion table guidelines.
Economic Considerations: While not the primary reason for conversion in this case, the dialysis unit later conducted a cost analysis showing a modest cost reduction with darbepoetin alfa compared to the previous epoetin alfa regimen when accounting for medication, administration, and storage costs.

This case illustrates the clinical benefits of converting from Procrit to Aranesp in a hemodialysis patient, particularly when adherence issues and hemoglobin stability are concerns. The evidence-based conversion approach resulted in improved clinical outcomes, better medication adherence, and enhanced patient quality of life.