What is the role of ulinastatin in preventing post‑endoscopic retrograde cholangiopancreatography (post‑ERCP) pancreatitis, including recommended dosing for low‑risk adults and its use in high‑risk patients?

Ulinastatin Has Limited Evidence and Is Not Recommended for Post-ERCP Pancreatitis Prevention

Ulinastatin is not included in current evidence-based guidelines for post-ERCP pancreatitis (PEP) prevention, and rectal NSAIDs (indomethacin or diclofenac 100 mg) remain the cornerstone pharmacologic intervention that should be administered to all eligible patients. 1

Guideline-Based Standard of Care

The 2017 BSG/Gut guidelines provide a strong recommendation with moderate-quality evidence that diclofenac or indomethacin 100 mg rectally should be administered at the time of ERCP to all patients without NSAID contraindications 1. This represents the most important pharmacologic advance in PEP prevention, supported by high-quality RCTs.

Notably absent from these guidelines is any mention of ulinastatin, despite its use in some Asian centers.

Research Evidence on Ulinastatin: Mixed and Contradictory

The research literature on ulinastatin shows conflicting results:

Potentially Favorable Data (Low-Average Risk Patients Only):

• Meta-analyses suggest benefit only in low-to-average risk patients when high-dose ulinastatin (150,000-200,000 U) is given before or during ERCP 2, 3
• One Japanese RCT (2005) showed reduced PEP incidence (2.9% vs 7.4%, p=0.041) with 150,000 U given immediately before ERCP 4

Negative Data (High-Risk Patients):

• A 2008 prospective RCT specifically in high-risk patients found NO benefit: Low-dose ulinastatin (100,000 U) given immediately after ERCP showed no difference in PEP rates (5.6% placebo vs 6.7% ulinastatin) 5
• A 2006 multicenter Japanese study found no significant difference between ulinastatin and gabexate, with PEP rates of 4.3-8.5% across groups 6

Critical Limitations:

• Dose inconsistency: Studies used 100,000-450,000 U with no consensus
• Timing variability: Before, during, or after ERCP
• Geographic limitation: Most positive studies from Asia; limited Western validation
• High-risk patients: The population most needing prophylaxis showed no benefit 5

Practical Algorithm for PEP Prevention

For ALL patients undergoing ERCP:

1. Rectal NSAIDs (100 mg indomethacin or diclofenac) - administer at time of ERCP unless contraindicated 1

2. High-risk patients (young, female, suspected sphincter of Oddi dysfunction, repeated pancreatic duct cannulation):

   • Consider prophylactic 5F pancreatic duct stent placement 1
   • Requires proper training; failed placement dramatically increases PEP risk

3. Avoid unnecessary pancreatic duct manipulation - minimize cannulation attempts and contrast injection 1

4. Aggressive hydration with lactated Ringer's may provide additional benefit 7, 8

Why Ulinastatin Is Not Recommended

The evidence hierarchy is clear: Guidelines prioritize interventions with consistent, high-quality evidence across diverse populations. Ulinastatin fails this standard because:

• No inclusion in major Western guidelines (BSG, ESGE, AGA) 1, 9
• Failed in the exact population needing it most (high-risk patients) 5
• Inconsistent dosing and timing protocols make standardization impossible
• Geographic limitation suggests possible publication bias or population-specific effects
• Rectal NSAIDs are superior: More consistent evidence, easier administration, lower cost

Common Pitfalls to Avoid

• Do not substitute ulinastatin for rectal NSAIDs - NSAIDs have the strongest evidence base
• Do not use low-dose ulinastatin (100,000 U) - this was specifically shown ineffective in high-risk patients 5
• Do not delay NSAID administration - give at time of ERCP, not after
• Do not attempt pancreatic stent placement without proper training - failed attempts worsen outcomes 1

Bottom Line

Rectal NSAIDs remain the evidence-based standard for PEP prophylaxis, with pancreatic duct stenting reserved for high-risk cases. While some Asian studies suggest potential benefit of high-dose ulinastatin (≥150,000 U) in low-risk patients, the lack of guideline endorsement, failure in high-risk populations, and availability of superior alternatives (NSAIDs) make it a non-recommended intervention in contemporary practice. The focus should remain on proven strategies: NSAIDs for all, selective stenting for high-risk patients, and meticulous technique to minimize pancreatic trauma.