Pain in chronic pancreatitis: Managing beyond the pancreatic duct

Table 1 Studies evaluating the role of antioxidant micronutrients on clinical outcomes, including pain, in patients with chronic pancreatitis

Ref.	Study type	Antioxidant micronutrients used	Indications; study duration	Outcomes
Uden et al[38] 1990	DB double dummy cross over	Vit C; Vit E; Beta carotene; Selenium; Methionine	n = 20 (ACP, ICP, IAP) 20 wk	↓ in VAS
De las Heras Castaño et al[39] 2000	Open label	Vit C; Vit E; Beta carotene; Selenium; Methionine	n = 19 (ACP, ICP, RAP) 12 mo	↓ in VAS,
				↓ admission,
				↑ exocrine fn
Dite et al[40] 2003	Open label	Vit C; Vit E	n = 70 (ACP, ICP) 12 mo	Pain abolished in 44%
Kirk et al[41] 2006	DB RCT cross over	Vit C; Vit E; Beta carotene; Selenium; Methionine	n = 19 (all ACP) 20 wk	↑ QOL
Bhardwaj et al[42] 2009	DB RCT	Vit C; Vit E; Beta carotene; Selenium; Methionine	n = 127 (ACP, ICP); 80% power; 6 mo	32% patients pain free
				↓ No. of painful days
				↓ analgesic need
Siriwardena et al[43] 2012	DB RCT	Vit C; Vit E; Beta carotene; Selenium; Methionine	n = 70 (ACP, ICP); 80% power; 6 mo	↔ pain
				↔ QOL

↓: Indicates reduction; ↑: Indicates improvement; ↔: Indicates equivocal. DB: Double blind; RCT: Randomized controlled trial; QOL: Quality of life; Vit: Vitamin; ACP: Alcoholic chronic pancreatitis; IAP: Idiopathic acute pancreatitis; RAP: Recurrent acute pancreatitis; fn.: Function; ICP: Idiopathic chronic pancreatitis.