Which drug should be given prophylactically to prevent tumor‑lysis syndrome in a 50‑year‑old man with bulky diffuse large B‑cell lymphoma receiving R‑CHOP?

Rasburicase Should Have Been Given Prophylactically

Rasburicase is the drug that should have been administered prophylactically to prevent tumor lysis syndrome (TLS) in this patient with bulky diffuse large B-cell lymphoma receiving R-CHOP. 1

Why This Patient Developed TLS

This patient presents with the classic triad of TLS after chemotherapy:

• Hyperkalemia (K 6.0) from massive intracellular potassium release 1
• Hyperphosphatemia (PO4 3.0) from intracellular phosphate release 1
• Hypocalcemia (Ca 1.2) from calcium-phosphate precipitation 1
• Acute kidney injury with oliguria (decreased urine output, elevated uric acid 570) representing a medical emergency 1

The combination of hyperkalemia and hypocalcemia in a lymphoma patient receiving R-CHOP is pathognomonic for TLS. 1

The Correct Prophylactic Drug: Rasburicase

Bulky disease is a high-risk feature that mandates rasburicase prophylaxis in patients with diffuse large B-cell lymphoma. 1 This patient had bulky DLBCL, which placed him at high risk for TLS before even starting chemotherapy.

Why Not the Other Options?

• Allopurinol is inferior to rasburicase for high-risk patients and only prevents new uric acid formation rather than eliminating existing uric acid 2, 3
• Furosemide is contraindicated in oliguric acute kidney injury and represents a fundamental misunderstanding of AKI management 1
• Thiazide has no role in TLS prevention or management 1

The Optimal Prevention Strategy

For this patient with bulky DLBCL, the ideal approach should have included:

1. Corticosteroid Pre-Phase Treatment

• Administer prednisone 100 mg orally daily for 5-7 days before initiating R-CHOP to reduce initial tumor burden and lower TLS risk 1, 4
• This pre-phase is mandatory for patients with high tumor burden (bulky disease) 4
• Do not delay definitive chemotherapy beyond 7 days after completing pre-phase 4

2. Rasburicase Prophylaxis

• Rasburicase prophylaxis is specifically recommended for patients with bulky disease 1
• Should be initiated before chemotherapy in high-risk patients 1
• The FDA-approved dose is 0.15-0.2 mg/kg IV over 30 minutes 2

3. Aggressive IV Hydration

• 2-3 L/m²/day to maintain urine output of at least 100 mL/m²/hour 1
• This is the cornerstone of TLS management alongside rasburicase 1

4. Close Monitoring

• Begin monitoring when pre-phase corticosteroids are initiated, as TLS can occur even before cytotoxic chemotherapy 4
• Continue through Day 7 post-chemotherapy for high-risk patients 4
• Monitor electrolytes and renal function closely 1

Critical Pitfalls to Avoid

• Do not use allopurinol alone in high-risk bulky disease—rasburicase is superior and specifically indicated 1, 3
• Do not use loop diuretics in oliguric patients—this worsens outcomes 1
• Do not reduce chemotherapy doses after pre-phase unless absolutely necessary, as dose reductions compromise treatment efficacy 1, 4
• Avoid urinary alkalinization, which is no longer recommended in TLS management 1

Current Management of Established TLS

Since this patient now has established TLS with oliguria and life-threatening hyperkalemia:

• Rasburicase immediately 1
• Aggressive management of hyperkalemia with calcium gluconate, insulin/dextrose, or sodium polystyrene sulfonate 1
• Urgent hemodialysis given the triad of oliguria, hyperkalemia, and TLS 1
• Do not delay dialysis if hyperkalemia is life-threatening or oliguria persists 1

The answer is rasburicase—it should have been given prophylactically before the first R-CHOP cycle in this patient with bulky DLBCL. 1