Pre-Treatment Screening Before Starting Krystexxa
Before initiating Krystexxa (pegloticase), you must screen for G6PD deficiency in at-risk patients and obtain a baseline serum uric acid level 1.
Mandatory Screening Requirements
G6PD Deficiency Testing
- Screen all patients of African or Mediterranean ancestry for G6PD deficiency before the first dose 1
- G6PD deficiency is an absolute contraindication due to risk of hemolysis and methemoglobinemia
- This is FDA-mandated screening, not optional
Baseline Laboratory Tests
- Serum uric acid level - essential for monitoring therapeutic response 1
- Baseline renal function (creatinine/eGFR) - to track kidney function during therapy
Pre-Treatment Medication Adjustments
Discontinue Oral Urate-Lowering Therapy
Stop all oral urate-lowering medications (allopurinol, febuxostat, probenecid) before starting Krystexxa 1. Continuing these agents can blunt the rise in serum uric acid that signals loss of therapeutic response, masking treatment failure and increasing anaphylaxis risk.
Initiate Gout Flare Prophylaxis
Start anti-inflammatory prophylaxis before the first infusion and continue for at least 6 months 1. Options include:
- Colchicine
- NSAIDs
- Prednisone/prednisolone
Choose based on patient comorbidities (renal function, cardiovascular disease, GI history).
Clinical Assessment Requirements
Cardiovascular Evaluation
- Assess for congestive heart failure history - Krystexxa has not been formally studied in CHF patients, and some experienced exacerbations in trials 1
- If CHF present, plan for close post-infusion monitoring
Confirm Appropriate Indication
Verify the patient has refractory chronic gout with:
- Serum uric acid ≥7 mg/dL despite oral ULT
- Failure/intolerance to conventional therapy (allopurinol, febuxostat)
- At least one of: tophi, chronic gouty arthritis, or ≥2 flares in past year
The 2020 ACR guidelines strongly recommend against pegloticase as first-line therapy 2 - ensure other options have been exhausted.
Infusion Preparation Checklist
Pre-Medication Protocol
All patients require pre-medication before each infusion 1:
- Antihistamine (e.g., diphenhydramine)
- Corticosteroid (e.g., methylprednisolone or prednisone)
Healthcare Setting Requirements
- Administer only in settings equipped to manage anaphylaxis
- Healthcare providers must be prepared to treat severe allergic reactions
- Plan for post-infusion observation period (approximately 1 hour minimum)
Common Pitfalls to Avoid
- Failing to screen G6PD in at-risk populations - this is a contraindication, not just a precaution
- Continuing oral ULT during Krystexxa therapy - this masks treatment failure and increases anaphylaxis risk
- Inadequate flare prophylaxis - gout flares are expected and should be prevented, not just treated reactively
- Insufficient monitoring capability - anaphylaxis can occur with the first infusion and requires immediate intervention capacity