Antidopaminergic drugs and acute pancreatitis: a population-based study

Objectives: To evaluate the suggested association between antidopaminergic drugs and acute pancreatitis. Design: A large population-based nested case-control study. Setting: Swedish nationwide study from 2006 to 2008. Participants: The Patient Register was used to identify 6161 cases of acute pancreatitis. The 61 637 control subjects were randomly selected from the Register of the Total Population by frequency-based density sampling, matched for age, sex and calendar year. Exposure: Exposure data were extracted from the Prescribed Drug Register. Antidopaminergic drugs were grouped into antiemetic/anxiolytic and other antipsychotics. Current use of antidopaminergic drugs was defined as filling a prescription 1-114 days before index date, while previous use was 115 days to 3.5 years before index date. Main outcome measures: Cases were defined as being diagnosed as having acute pancreatitis. ORs and 95% CIs were calculated using unconditional logistic regression. Results: The unadjusted OR indicated an increased risk of acute pancreatitis among current users of antiemetic/anxiolytics (OR 1.9, 95% CI 1.4 to 2.6), but not in the multivariable model adjusting for alcohol-related comorbidity, chronic obstructive lung disease, ischaemic heart disease, obesity, diabetes, opioid use, gallstone disease, educational level, marital status and number of concomitant medications (OR 0.9, 95% CI 0.6 to 1.2). Similarly, among current users of other antipsychotics, the unadjusted OR was 1.4 (95% CI 1.1 to 1.6), while the adjusted OR was 0.8 (95% CI 0.6 to 0.9). Results regarding previous use of antidopaminergic drugs followed a similar risk pattern as for current use. Conclusions: The lack of association between antidopaminergic drugs and acute pancreatitis after adjustment for confounding factors in this study suggests that the previously reported positive associations might be explained by confounding.