Increased risk of acute pancreatitis among tetracycline users in a Swedish population-based case–control study

To evaluate the suggested association between tetracycline and acute pancreatitis in a large pharmacoepidemiological study.The use of tetracycline in relation to the risk of acute pancreatitis was examined in a nationwide case-control study of people aged 40-84 years between 2006 and 2008 in Sweden. The Swedish Patient Register was used to identify 6161 cases of first-episode acute pancreatitis. The Register of the Total Population was used to randomly select 61,637 control subjects from the general population using frequency-based density sampling, matched for age, sex, and calendar year. Tetracycline use was defined as 'current', 'recent', 'past' or 'former' if the drug had been dispensed 0-30 days, 31-180 days, 181-365 days or 1-3½ years before the index date, respectively. The risk of acute pancreatitis was estimated by unconditional logistic regression, providing ORs with 95% CIs, adjusted for potential confounding factors.There was a 60% increased risk of acute pancreatitis among current users of tetracycline after adjustment for potential confounders (OR=1.6, 95% CI 1.2 to 2.1). There was no increased OR for any category of previous use.Current use of tetracycline is associated with an increased risk of acute pancreatitis, verifying previous case reports.