Important Clarification: Uzedy vs. Pegfilgrastim
The question asks about "Uzedy," but the evidence provided pertains to pegfilgrastim (a granulocyte colony-stimulating factor), not Uzedy (which is risperidone extended-release injectable suspension for schizophrenia). These are completely different medications for different indications. I will provide dosing information for pegfilgrastim based on the evidence supplied, but please confirm the intended medication.
Pegfilgrastim Dosing Guide
Standard Prophylactic Dosing
Administer pegfilgrastim as a single fixed dose of 6 mg subcutaneously once per chemotherapy cycle, starting 24-72 hours after completion of chemotherapy. 1, 2
Key Dosing Parameters:
- Fixed dose: 6 mg per cycle (not weight-based) 1, 2
- Route: Subcutaneous injection (preferred route) 1
- Timing: Administer 24-72 hours after chemotherapy completion (Category 1 recommendation for next-day administration) 1, 3
- Frequency: One dose per chemotherapy cycle only 1
Timing Considerations:
- Next-day administration (24 hours post-chemotherapy): Category 1 evidence, most strongly supported 1
- Administration up to 3-4 days post-chemotherapy: Reasonable based on filgrastim trials 1
- Same-day administration: May be considered in certain circumstances for logistical reasons, though limited data show a trend toward longer neutropenia duration 1
Critical Warning: Never administer pegfilgrastim on the same day as chemotherapy administration—this increases febrile neutropenia and adverse events 1
Chemotherapy Cycle Length Restrictions:
- Every 3-week regimens: Category 1 evidence supports use 1
- Every 2-week regimens: Phase II studies demonstrate efficacy; use is reasonable 1, 4
- Weekly regimens or cycles <2 weeks: Insufficient data; pegfilgrastim cannot be recommended 1
Pediatric Dosing:
- Weight ≥45 kg: 6 mg fixed dose 1, 2
- Weight <45 kg: The 6 mg prefilled syringe is not recommended; consider alternative formulations or filgrastim instead 1, 2
- Weight-based alternative: 100 mcg/kg has been studied in pediatric sarcoma patients 2
Special Populations:
Renal Impairment:
- No dose adjustment required—pegylation renders renal clearance insignificant 5
Hepatic Impairment:
- No specific dosing adjustments provided in guidelines 2
Duration of Therapy:
Pegfilgrastim is self-limiting: Serum concentrations remain elevated during neutropenia but decline rapidly when neutrophil recovery occurs (typically when ANC ≥1 × 10⁹/L post-nadir) 5. No additional doses are needed within the same chemotherapy cycle 1.
Common Pitfalls to Avoid:
Do not administer pegfilgrastim for concurrent chemotherapy and radiation therapy—prophylactic use is not recommended in this setting 1
Do not use for weekly chemotherapy regimens—insufficient evidence for safety and efficacy 1
Do not give multiple doses per cycle—the pharmacokinetics are self-regulating through neutrophil-mediated clearance 5
Do not use the prefilled syringe for partial doses in pediatric patients <45 kg—the syringe lacks graduation marks and is designed only for full 6 mg administration 2
Contraindications:
Absolute contraindication: History of serious allergic reactions to pegfilgrastim products or filgrastim products 2
Monitoring:
Continue pegfilgrastim until post-nadir ANC recovery to ≥2-3 × 10⁹/L, which serves as a surrogate marker for clearance to subtherapeutic levels 3, 5