What is the typical dosing for Retacrit (epoetin alfa) in patients with anemia?

Retacrit (Epoetin Alfa) Dosing Guidelines

The recommended starting dose of Retacrit (epoetin alfa) is 150 IU/kg three times weekly subcutaneously for chemotherapy-associated anemia, or 40,000 units once weekly as an alternative regimen, with dose adjustments based on hemoglobin response. 1

Dosing Based on Clinical Indication

Chemotherapy-Induced Anemia

• Starting dose: 150 IU/kg three times weekly subcutaneously for minimum 4 weeks 1
• Alternative regimen: 40,000 units once weekly subcutaneously 1, 2
• Dose escalation: If inadequate response after 4 weeks, increase to 300 IU/kg three times weekly for additional 4-8 weeks 1
• Target hemoglobin: 10-12 g/dL (initiate when Hb approaches or falls below 10 g/dL) 1

Chronic Kidney Disease (CKD)

• Hemodialysis patients:

  • IV administration: 50% higher than SC dose (typically 120-180 IU/kg/week in three divided doses) 1
  • Initial IV dose: 120-180 IU/kg/week (typically 9,000 units/week) in three divided doses 1, 3

• Non-dialysis CKD patients:

  • SC administration: 80-120 IU/kg/week (typically 6,000 units/week) 3
  • Alternative: 10,000 units SC once weekly 4

• Peritoneal dialysis patients:

  • SC administration preferred
  • Intraperitoneal administration possible but requires higher doses 1

Route of Administration Considerations

1. Subcutaneous (SC):

   • Preferred for non-dialysis CKD and peritoneal dialysis patients
   • More efficient than IV (requires ~33% less drug for same effect) 1, 3
   • Divide doses and rotate injection sites to minimize discomfort 1

2. Intravenous (IV):

   • Common for hemodialysis patients during dialysis sessions
   • Requires approximately 50% higher doses than SC 1, 3
   • Inject into arterial or venous blood lines during hemodialysis 1

3. Intraperitoneal (IP):

   • Reserved for peritoneal dialysis patients when SC/IV not feasible
   • Administer into dry abdomen or with minimal dialysate
   • Higher dose requirements than SC/IV 1

Monitoring and Dose Adjustments

• Initial monitoring: Check hemoglobin weekly until stable, then monthly 3
• Dose reduction: Decrease dose by 25% if hemoglobin increases >1 g/dL in any 2-week period 1, 3
• Dose increase: If inadequate response (Hb increase <1 g/dL) after 4-6 weeks, increase dose as indicated above 1
• Target hemoglobin: Maintain between 10-12 g/dL 3
• Withholding therapy: Consider if Hb increases rapidly (>8 percentage points in a month); resume at 75% of previous dose 1

Important Clinical Considerations

• Iron status: Ensure adequate iron stores before and during therapy (TSAT >20%, ferritin >100 ng/mL) 1, 3
• Safety concerns: Higher hemoglobin targets (>12 g/dL) achieved with ESAs have been associated with increased stroke and thrombotic event risk 3, 5
• Response rate: Approximately 90% of patients respond to once-weekly dosing with an increase in Hb ≥1 g/dL 4
• Quality of life: Significant improvements in energy, activity and overall quality of life are associated with Hb increases 4, 2

Practical Dosing Tips

• Use the smallest gauge needle (e.g., 29 gauge) for SC injections to minimize discomfort 1
• For patients unable to tolerate SC administration, switch to IV with appropriate dose adjustment 1
• When converting from IV to SC in patients with stable Hb, reduce weekly dose to approximately two-thirds of the IV dose 1
• For pediatric patients, dosing may need to be higher in children <5 years of age 1

Remember that the primary goal of therapy is to reduce transfusion requirements and improve quality of life while minimizing risks of thrombotic events by maintaining hemoglobin within the target range of 10-12 g/dL.