Antioxidant Therapy Does Not Reduce Pain in Patients with Chronic Pancreatitis: The ANTICIPATE Study

Abstract

Background & Aims: We investigated whether antioxidant therapy reduces pain and improves quality of life in patients with chronic pancreatitis. Methods: We performed a double-blind, randomized, controlled trial that compared the effects of antioxidant therapy with placebo in 70 patients with chronic pancreatitis. Patients provided 1 month of baseline data and were followed up for 6 months while receiving either Antox version 1.2 (Pharma Nord, Morpeth, UK) or matched placebo (2 tablets, 3 times/d). The primary analysis was baseline-adjusted change in pain score at 6 months, assessed by an 11-point numeric rating scale. Secondary analyses included alternative analyses of clinic and diary pain scores, scores on quality-of-life tests (the EORTC-QLQ-C30, QLQ-PAN28, EuroQOL EQ-5D, and EQ visual analog score), levels of antioxidants, use of opiates, and adverse events. Analyses, reported by intention to treat, were prospectively protocol-defined. Results: After 6 months, pain scores reported to the clinic were reduced by 1.97 from baseline in the placebo group and by 2.33 in the antioxidant group but were similar between groups (−0.36; 95% confidence interval, −1.44 to 0.72; P = .509). Average daily pain scores from diaries were also similar (3.05 for the placebo group, 2.93 for the antioxidant group, a difference of 0.11; 95% confidence interval, 1.05–0.82; P = .808). Measures of quality of life were similar between groups, as was opiate use and number of hospital admissions and outpatient visits. Blood levels of vitamin C and E, β-carotene, and selenium were increased significantly in the antioxidant group. Conclusi1ons: In patients with painful chronic pancreatitis of predominantly alcoholic origin, antioxidant therapy did not reduce pain or improve quality of life, despite causing a sustained increase in blood levels of antioxidants. Trial registration: ISRCTN-21047731.