Incidence, severity, and etiology of drug-induced acute pancreatitis.

Introduction: Drug-induced acute pancreatitis is considered to be a rare diagnosis. The incidence of drug-induced acute pancreatitis is usually estimated from case reports.

Aim: The aim of this study was to determine the incidence, etiology, and severity of drug-induced pancreatitis during a 2-year period in a tertiary hospital.

Methods: The study was conducted as a retrospective analysis of all cases of pancreatitis in the University Hospital in Olomouc (1,432 beds) in 2006-2007. All cases of acute pancreatitis were re-evaluated and divided according to the causative factor. In drug-induced cases, the WHO Probability Scale for the evaluation of causality relationship was used.

Results: The inclusion criteria were met by 170 medical files. There were 91 (53%) cases in men and 79 (47%) in women, and mean age was 57 years old (5-91 years old). The etiology was in 53% biliary, 31% alcohol-induced, 12% other determined, and in 4% the cause could not be established. The proportion of drug-induced acute pancreatitis was 5.3% and it was the third most frequent cause of the AP. Azathioprine was the most frequent causative factor (three cases in two patients); all the other causative drugs were documented only in single cases: mesalazine, dexamethasone, ramipril, mycophenolate mofetil, cytarabine, and valproate.

Conclusions: The diagnosis of drug-induced acute pancreatitis seems to be underestimated because of the difficulties in determining the causative agent and the need for a retrospective re-evaluation of the suspected causative factors. The disease is more probable in younger persons, women, and patients suffering from Crohn's disease.