Do H-2-receptor antagonists cause acute pancreatitis?

The aim of this study was to investigate the association between H-2-recept or antagonists and acute pancreatitis. The automated database of the Medici nes Monitoring Unit (MEMO) was used to carry out a case-control study, supp lemented with information on possible confounding factors from hospital and GP medical records. Cases were patients hospitalized with a computerized d iagnosis of acute pancreatitis, and two sets of controls were drawn from (1 ) the study population and from (2) the same GP practice as the case. Curre nt or 60-day exposure to cimetidine and ranitidine was analysed. In adjuste d analyses, cimetidine exposure and ranitidine exposure were associated wit h an increased risk of hospitalization for acute pancreatitis, as were alco hol abuse and cholelithiasis. The risks were lower in unadjusted analyses, suggesting that the association is confounded, although they did not disapp ear completely. A possible explanation is that data on confounding were inc omplete. This study cannot discount the existence of an association between H-2-antagonists and acute pancreatitis, and highlights the difficulties in volved in obtaining complete and accurate data on confounding factors that are not collected routinely. (C) 1998 John Wiley & Sons, Ltd.