Oral allopurinol to prevent hyperamylasemia and acute pancreatitis after endoscopic retrograde cholangiopancreatography

Table 3 Summary of randomized trials using allopurinol to prevent post-ERCP pancreatitis

Study (year), SC vs MC, country	n	Dose, mg	Allopurinol vs placebo PEP rates	Percentage high risk1	Comment
Budzyńska et al[31] (2001) SC, Poland	300	4002	12.1% vs 7.9%; 12 vs 8	0	3-arm study, with third arm (n = 100) given prednisone
Kastinelos et al[30] (2005) SC, Greece	250	12003	3.2% vs 17.8%; 4 vs 21	0	2 patients with suspected SOD
Mosler et al[32] (2005) MC, USA	701	9004	13.0% vs 12.1%; 46 vs 42	70.2	4% absolute benefit in high-risk patients; 4% absolute harm in average risk
Romagnuolo et al[33] (2008) MC, Canada	586	3005	5.5% vs 4.1%; 16 vs 12	11.3	Harm in average risk patients; benefit in high-risk patients
Current study (2009) SC, Mexico	170	6006	2.3% vs 9.4%; 2 vs 8	34.1	21.7% absolute benefit in patients with high-risk procedures favoring allopurinol, no difference in low-risk procedures
Raw pooled	2007 (1008 vs 999)	-	7.9% vs 9.1%; 80 vs 91	-	1.2% difference (95% CI, 3.2% to 2.0%)

¹As defined in this protocol, namely sphincter manometry and/or pancreatic therapy. Other higher-risk cases (e.g. precut sphincterotomy or suspected SOD) were not considered;

²200 mg 15 h before, 200 mg 3 h before;

³600 mg 15 h before, 600 mg 3 h before;

⁴600 mg 4 h before, 300 mg 1 h before;

⁵300 mg 1 h before;

⁶300 mg 15 h before, 300 mg 1 h before; SC: Single centre; MC: Multicenter.