ACUTE PANCREATITIS SECONDARY TO LONG TERM 5-AMINOSALICYLIC ACID THERAPY - A CASE SERIES AND REVIEW OF THE LITERATURE

A Bedi, M Alghamdi, D Farina, GK Turnbull

Department of Gastroenterology, Dalhousie University, Halifax, Nova Scotia

Acute pancreatitis is a known adverse effect of 5-aminosalicyclic acid (5-ASA), usually occurring after short term 5-ASA therapy. The aim of this study is to present two cases of acute pancreatitis occurring after long term 5-ASA therapy, and review the literature with regard to prevalence and mechanism of 5-ASA induced acute pancreatitis.
A literature search with Pubmed from 1965 to present identified only one case series of two patients with acute pancreatitis after long term 5-ASA therapy (more than three months). We present the first Canadian series, and second series overall, of acute pancreatitis secondary to long term 5-ASA therapy; proven by rechallenge with 5-ASA.
A 34 year old woman with ileocolonic Crohn's disease was admitted with acute onset of epigastric and left flank pain. The serum amylase and lipase were both elevated to 193 and 418, respectively. The patient had been taking Salofalk 4 grams/day for two years, which was held on admission. Abdominal ultrasound on the first day of admission was normal, but two days later revealed a hypoechoic and slightly enlarged pancreas, consistent with acute pancreatitis. After five days, the patient's pain had resolved; the amylase and lipase both had markedly diminished to 198 and 57, respectively. After discharge, the patient rechallenged herself with Salofalk, with subsequent recurrence of epigastric pain identical in character to that which she was admitted with previously. She refused further therapy with 5-ASA.
A 23 year old man with ulcerative colitis presented with epigastric pain and elevated lipase of 213. The patient had been taking Salofalk daily for one year, and intermittently for three years previous to that. Salofalk was held on admission, and within 24 hours the patient's pain resolved. Serum lipase declined to 44 within 24 hours. After recovery, the patient was rechallenged with Salofalk, epigastric pain recurred and lipase was elevated to 368.
The mechanism of acute pancreatitis secondary to long term 5-ASA therapy is unknown. A possible proxoidant or allergy mechanism has been postulated.