Side Effects of Retacrit (Epoetin Zeta) IV
Retacrit (epoetin zeta) IV administration is associated with several significant side effects, most notably an increased risk of thromboembolic events (67% higher risk compared to placebo) and potential impact on mortality in certain cancer populations. 1
Major Side Effects
Cardiovascular and Thromboembolic Events
- Thromboembolic events: 67% increased relative risk compared to placebo (RR 1.67; 95% CI 1.35-2.06) 1
- Hypertension: Common adverse effect, particularly in patients with pre-existing hypertension 1, 2
- Increased mortality risk: In cancer patients not receiving chemotherapy or when targeting hemoglobin levels above 12 g/dL 2
Hematologic Effects
- Pure red cell aplasia (PRCA): Caused by neutralizing anti-erythropoietin antibodies, primarily observed in chronic renal failure patients 1
- Thrombocytosis: May occur during treatment 3
Other Common Side Effects
- Injection site reactions: Pain at injection site (usually mild and transient) 1
- Allergic reactions: Including dyspnea, skin rash, and urticaria 1
- Musculoskeletal: Arthralgia 1
- Peripheral edema 1
- Flu-like symptoms: Headache and general malaise 3
- Electrolyte disturbances: Hyperkalemia has been reported 3
Risk Factors for Adverse Events
Patients with the following conditions have higher risk of complications and require careful monitoring:
- History of thrombosis 1, 2
- Recent surgery 1
- Prolonged immobilization or limited activity 1
- Poorly controlled hypertension: Contraindicated in these patients 1
- Liver disease: Use with caution due to unknown effects 1
- Multiple myeloma patients treated with thalidomide or lenalidomide in combination with doxorubicin and corticosteroids 1, 2
Monitoring Recommendations
- Blood pressure: Regular monitoring, especially in patients with pre-existing hypertension 1
- Hemoglobin levels: Target should not exceed 12 g/dL; reduce dose if Hb rises >2 g/dL in 4 weeks 1, 2
- Iron status: Baseline and periodic monitoring of iron, transferrin saturation, and ferritin levels 1
- Renal function: Assess before initiating therapy 2
Contraindications
- Uncontrolled hypertension 1
- Known hypersensitivity to epoetin or any excipients 1
- Cancer treatment with curative intent 2
- Patients not receiving concurrent chemotherapy 2
Clinical Considerations
- ESAs like Retacrit should be used at the lowest dose needed to avoid transfusions 2
- Discontinue if no response after 6-8 weeks of appropriate dosing 2
- Discontinue when chemotherapy concludes 2
- The FDA recommends discussing potential harms (thromboembolism, shorter survival) and benefits (decreased transfusions) with patients 2
While Retacrit is effective in treating anemia in various conditions, the risk-benefit profile must be carefully evaluated for each patient, with particular attention to thromboembolic risk factors and treatment goals.