CRESP 100

1. Definition & Composition

• Generic Name: Darbepoetin Alfa

• Strength: 100 mcg per dose (single-use vial/prefilled syringe)

• Class: Long-acting Erythropoiesis-Stimulating Agent (ESA)

• Mechanism: Stimulates red blood cell production in bone marrow

• Composition:

  • Active: Darbepoetin Alfa (recombinant glycoprotein)

  • Inactive: Sodium phosphate, polysorbate 80, sucrose

2. Importance & Clinical Significance

• Primary Use: Treatment of anemia in:

  • Chronic Kidney Disease (CKD) patients (both dialysis and non-dialysis)

  • Chemotherapy-induced anemia in cancer patients

• Key Benefits:

  • Reduces need for blood transfusions

  • Longer half-life allows less frequent dosing (weekly or biweekly)

  • Improves quality of life by alleviating anemia symptoms

3. Indications & Uses

✅ Approved Uses:

• Anemia associated with CKD

• Anemia in cancer patients receiving chemotherapy

• May be used for HIV patients with zidovudine-induced anemia

🚫 Not Recommended For:

• Treatment of anemia due to iron or vitamin deficiencies

• Patients with uncontrolled hypertension

• Myeloid malignancies (e.g., AML, CML)

4. Dosage & Administration

Important Notes:

• Always use the lowest effective dose

• Monitor hemoglobin weekly until stable

• Adjust dose to maintain Hb between 10-12 g/dL

• Requires adequate iron stores (ferritin >100 ng/mL)

5. Side Effects & Adverse Reactions

Common (≥10%):

• Hypertension (most frequent)

• Headache, dizziness

• Injection site reactions

• Nausea, diarrhea

• Muscle pain

Serious (Require Immediate Attention):

• Thromboembolic events (DVT, PE, stroke)

• Pure Red Cell Aplasia (PRCA)

• Severe allergic reactions

• Seizures (in CKD patients)

• Tumor progression in cancer patients

6. Storage & Handling

• Temperature: 2-8°C (refrigerate, do not freeze)

• Protection: Keep in original packaging (light-sensitive)

• Stability: Do not shake (may cause protein degradation)

• Expiration: Discard unused portion (single-use vial)

7. Contraindications & Warnings

❌ Absolute Contraindications:

• Uncontrolled hypertension

• Pure Red Cell Aplasia after ESA therapy

• Hypersensitivity to darbepoetin alfa

⚠️ Boxed Warnings (FDA):

• Increased risk of death, MI, stroke, and thrombosis

• Increased risk of tumor progression in cancer patients

• Higher risk when Hb >12 g/dL

8. Drug Interactions

• May enhance hypertensive effect of other drugs

• Reduced efficacy in iron-deficient patients

• Caution with other drugs affecting erythropoiesis

9. Monitoring Requirements

• Weekly Hb monitoring until stable

• Monthly iron studies (ferritin, TSAT)

• Regular blood pressure checks

• Monitor for signs of thrombosis

10. Conclusion

CRESP 100 (Darbepoetin Alfa 100 mcg) is a high-potency ESA for managing severe anemia in CKD and chemotherapy patients. Its use requires:

• Careful patient selection

• Strict Hb monitoring (10-12 g/dL target)

• Adequate iron supplementation

• Vigilance for thrombotic complications

Clinical Pearls:

1. Always start with the lowest effective dose

2. Never use to replace emergency transfusions

3. Discontinue after chemotherapy completion

4. Consider discontinuing if no response after 8 weeks