Pegfilgrastim

# Pegfilgrastim ## Overview - **Classification**: Granulocyte Colony-Stimulating Factor (G-CSF) - **Mechanism**: Stimulates proliferation, differentiation, and activation of neutrophils, leading to increased neutrophil production. This reduces the incidence of febrile neutropenia (FN). ## Primary Indications 1. **Febrile Neutropenia Prophylaxis** - Decrease infection incidence in non-myeloid cancer patients receiving myelosuppressive chemotherapy. 2. **Acute Radiation Syndrome (H-ARS)** - Increase survival in patients acutely exposed to myelosuppressive doses of radiation. ## Adult Dosing ### Standard Dosing **Febrile Neutropenia Prophylaxis** - **Dose**: **6 mg** - **Frequency**: Once per chemotherapy cycle - **Route**: Subcutaneous (SC) - **Special Considerations**: Administer >**24 hours** after chemotherapy, and at least **14 days** before the next chemotherapy. **Acute Radiation Syndrome (H-ARS)** - **Dose**: **6 mg** - **Frequency**: Once. A second **6 mg** dose may be given 1 week later if ANC <500/mm^3. - **Route**: Subcutaneous (SC) - **Special Considerations**: Administer as soon as possible after suspected/confirmed radiation exposure. ### Dose Adjustments - **Renal Impairment**: No specific dose adjustment recommended. - **Hepatic Impairment**: No specific dose adjustment recommended. - **Elderly Patients**: No specific dose adjustment needed. Efficacy and safety are similar to younger adults. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Not routinely recommended. - **Special Notes**: Safety and efficacy have not been established in neonates. ### Infants (1-12 months) - **Dose**: Not routinely recommended. - **Special Notes**: Safety and efficacy have not been established in infants. ### Children (2-12 years) **Febrile Neutropenia Prophylaxis** - **Dose**: - Body weight <**45 kg**: **0.1 mg/kg** - Body weight ≥**45 kg**: **6 mg** - **Frequency**: Once per chemotherapy cycle - **Route**: Subcutaneous (SC) - **Maximum**: **6 mg** per dose. - **Special Notes**: Administer >**24 hours** after chemotherapy, and at least **14 days** before the next chemotherapy. Approved for patients **>2 years** of age. **Acute Radiation Syndrome (H-ARS)** - **Dose**: - Body weight <**45 kg**: **0.1 mg/kg** - Body weight ≥**45 kg**: **6 mg** - **Frequency**: Once. A second dose (0.1 mg/kg or 6 mg) may be given 1 week later if ANC <500/mm^3. - **Route**: Subcutaneous (SC) - **Maximum**: **6 mg** per dose. - **Special Notes**: Administer as soon as possible after suspected/confirmed radiation exposure. Approved for patients **>2 years** of age. ### Adolescents (13-18 years) **Febrile Neutropenia Prophylaxis & H-ARS** - **Dose**: Follow adult dosing: **6 mg** - **Frequency**: As per adult regimen (once per chemo cycle or as a single dose for H-ARS). - **Maximum**: **6 mg** per dose. - **Special Notes**: Administer >**24 hours** after chemotherapy (for FN) and avoid within 14 days of next cycle. ## Safety Information ### Contraindications - **Absolute**: History of serious allergic reactions to pegfilgrastim or filgrastim. ### Common Adverse Effects - **Very Common (>10%)**: Bone pain, body aches. - **Common (1-10%)**: Nausea, fatigue, injection site reactions, headache. - **Serious but Rare**: Splenic rupture (left upper abdominal pain/shoulder pain), Acute Respiratory Distress Syndrome (ARDS), severe allergic reactions (anaphylaxis), sickle cell crisis, glomerulonephritis, aortitis. ### Key Drug Interactions - **Chemotherapy**: Do NOT administer within **24 hours** before or after chemotherapy. May increase myelosuppression. - **Lithium**: May potentiate myeloproliferative effects; monitor WBC counts closely. ## Monitoring & Follow-up - **Before Treatment**: Obtain a baseline Complete Blood Count (CBC) with differential. - **During Treatment**: Monitor CBC with differential periodically (e.g., before each subsequent chemotherapy cycle). - **Clinical Signs**: Monitor for signs of splenic enlargement/rupture (left upper abdominal pain, shoulder tip pain), ARDS (fever, dyspnea), or allergic reactions. ## Clinical Pearls - 💡 **Timing is Key**: Administer **>24 hours** post-chemo and at least **14 days** prior to the next planned chemo cycle. - 💡 **Storage**: Store refrigerated (2-8°C). Protect from light. Allow to reach room temperature for 30 minutes before injection. Do NOT freeze. - 💡 **Administration**: Do NOT shake vigorously. Discard any vial/syringe exposed to room temperature for >48 hours. - 💡 **Pain Management**: Bone pain is common. Consider NSAIDs or antihistamines (e.g., loratadine) for pain relief. - 💡 **On-Body Injector (Onpro)**: If using Onpro, ensure proper placement and patient education on its use and removal. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.