Pancreatic Enzyme Supplements

PANCREATIC ENZYME SUPPLEMENTS

Some 90% of patients with cystic fibrosis receive pancreatic enzyme supplements for management of the symptoms of exocrine pancreatic insufficiency (FitzSimmons, 1993). By reducing steatorrhea and faecal fat excretion, the supplements improve the nutritional status of the patient. Pancreatic extracts have been used for many years, but in 1994, five cases of stricture of the ascending colon in chil-dren with cystic fibrosis who were receiving extracts were published (Smyth et al., 1994). Additional cases (Campbell, Forrest and Musgrove, 1994; McHugh, Thomson and Tam, 1994; Oades et al., 1994; Freiman and FitzSimmons, 1996; FitzSimmons et al., 1997) suggested that the strictures appeared to be tempo-rally related to the recent introduction of high-dose pancreatic supplements.

These reports, and a further 35 cases of colonic stricture reported to the US Cystic Fibrosis Founda-tion, prompted the Foundation to organise a Consen-sus Conference to examine the use of pancreatic enzymes in patients with cystic fibrosis (Borowitz et al., 1995). The Conference used the term ‘fibros-ing colonopathy’ to describe ‘a condition associated with ingestion of large quantities of pancreatic enzyme supplements’ and which leads to colonic strictures. It was considered that patients at highest risk were those who were less than 12 years of age, have taken more than 6000 lipase units per kilogram per meal for more than 6 months, have a history of meconium ileus or distal intestinal obstruction, have had intesti-nal surgery or have a diagnosis of inflammatory bowel disease.

Although it was initially suspected that it was high-dose pancreatic supplements only that were caus-ing fibrosing colonopathy, subsequently there were reports of the condition in children with cystic fibrosis who were receiving low-dose preparations (Jones et al., 1995; Taylor and Steiner, 1995; Freiman and FitzSimmons, 1996; O’Keefe, 1996). However, a dose-related risk for the development of fibros-ing colonopathy has been suggested (Smythe et al., 1995; Bakowski and Prescott, 1997; FitzSimmons et al., 1997).

A detailed review of early cases of fibrosing colonopathy and the chronology of events following the introduction in the United Kingdom and the United States of new forms of pancreatic supplements has been published (Bakowski and Prescott, 1997). The authors suggest that the patterns of use of the pancre-atic supplements and the development of fibrosing colonopathy are highly suggestive of a dose-related causal role for preparations of which methacrylic acid co-polymer is a constituent of the enteric coating. This confirmed an earlier observation that methacrylic acid could be a key factor in the development of fibrosing colonopathy (van Velzen, 1995).

More recently, there have been anecdotal case reports of fibrosing colonopathy in two adult patients receiving pancreatic enzyme supplements (Hausler et al., 1998; Bansi et al., 2000). The first was of a 25-year-old woman who developed symptomatic fibrosing colonopathy several months after begin-ning high-dose (17 000 lipase units per kilogram per day) pancreatic enzyme therapy (Hausler et al., 1998). The second involved a woman in her late 20s who had undergone cholecystectomy for gallstone disease followed thereafter by endoscopic management of common bile duct stones (Bansi et al., 2000). She later underwent a pylorus-preserving pancreaticoduodenec-tomy and in the subsequent 7 years received large amounts of pancreatic enzyme supplements. After developing a large bowel obstruction, a right hemi-colectomy was undertaken and fibrosing colonopathy of the ascending colon and caecum was confirmed by histology.