The effect of cimetidine on maldigestion in cystic fibrosis.

Ten patients (6 to 27 years of age) who had severe pancreatic 
exocrine insufficiency due to cystic fibrosis were studied to determine whether 
cimetidine would improve dietary fat and nitrogen absorption. When a constant 
diet was consumed and oral pancreatic enzymes were administered, the addition 
of cimetidine (150 or 200 mg taken orally one-half hour before 
meals) signficantly reduced fecal fat excretion from 25.3 +/- 2.9 to 
17.3 +/- 2.1 gm/24 hours and fecal nitrogen excretion from 4.5 
+/- 0.6 to 3.4 +/- 0.5 gm/24 hours (P less than 
0.05). Lower doses of cimetidine resulted in less significant reductions of 
steatorrhea and azotorrhea. Cimetidine may be a useful adjunct to oral 
pancreatic enzyme therapy in patients with cystic fibrosis who continue to 
have steatorrhea and azotorrhea with enzyme therapy alone. 