Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The failure of standard oral pancreatic enzyme replacement therapy to correct malabsorption in patients with advanced pancreatic insufficiency is likely due to acid-peptic inactivation of ingested enzymes. Theoretically, the use of cimetidine, an H2-receptor antagonist, in conjunction with oral enzymes, would permit greater transgastric passage of ingested enzymes with resulting improvement in intraluminal lipolysis. To test this hypothesis, we studied the effects of orally administered cimetidine in two groups of patients by utilizing a previously validated double-marker perfusion technique. Cimetidine, in varying doses, had no effect on postprandial exocrine pancreatic function in 16 duodenal ulcer patients without pancreatic disease. In six patients with pancreatic insufficiency, cimetidine produced a pronounced decrease in the output of gastric acid and secretory volume, resulting in reduction of postprandial acidity and intragastric volume. These actions of cimetidine should retard or prevent inactivation of ingested enzymes and also increase their intragastric concentration, with resulting enhancement of luminal duodenal enzyme activity. Supplemental cimetidine may thus be useful in the medical management of patients who fail to respond to routine pancreatic extract therapy alone.
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PMID:Rationale for the use of cimetidine in pancreatic insufficiency. 34 Aug 5

A case of the Zollinger-Ellison syndrome, presented with watery diarrhoea, malabsorption and multiple duodenal ulcers. Resection of a gastrinoma from the head of the pancreas was ineffective. Cimetidine, administered for more than 30 months produced an immediate and sustained relief of symptoms with a gain in weight of 19 kg and improvement of the biochemical features of malabsorption. Gastric acid secretion has been markedly inhibited and duodenal ulceration healed.
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PMID:A review of the Zollinger-Ellison syndrome--with particular reference to a patient treated with cimetidine. 53 59

Histamine H2-receptor antagonists are widely used in the treatment of gastrointestinal diseases related to gastric acid hypersecretion. Cimetidine was introduced into medical practice in 1976 and ranitidine, famotidine and nizatidine in 1981, 1985 and 1987, respectively. Haematological adverse effects are relatively uncommon and most have been reported in cases of cimetidine administration. These adverse effects are reviewed under 4 main headings: (a) blood cytopenias and leucocytosis; (b) coagulation disorders related to drug interactions with oral anticoagulants; (c) reduction of dietary iron absorption; and (d) reduction of dietary cobalamin absorption. 85 reported cases of blood cytopenias attributed to these drugs are reviewed, of which 75 (88%) were associated with cimetidine therapy. In postmarketing surveillance studies, the incidence of cimetidine-associated blood cytopenia has been evaluated at about 2.3 per 100,000 patients. Neutropenia and agranulocytosis are by far the most frequently encountered. Whatever the drug or the type of cytopenia, this adverse effect is almost always rapidly reversible when treatment is stopped. Moreover, in several cases other factors such as underlying diseases or additional drugs could have been responsible, at least partly, for the cytopenia. The pathophysiological basis of these adverse effects remains poorly explained. Various mechanisms have been proposed, which in some cases are probably associated: (a) direct toxicity for haemopoietic stem cells; (b) drug-induced immune reactions leading to blood or bone marrow cell damage, and (c) drug interactions, with increased and prolonged action of potentially haematotoxic drugs. Mechanisms (a) and (c) appear to be of particular clinical importance in cases of impaired renal elimination of H2-receptor antagonists. Cimetidine and probably to a lesser extent ranitidine potentiate the action of oral anticoagulants of both coumarin and indanedione structure. This may result in haemorrhagic complications. Such action is a consequence of the reduced hepatic metabolism of oral anticoagulants through a dose-dependent, reversible inhibition of cytochrome P450. Malabsorption of dietary iron and cobalamin appears to result from inhibition of gastric secretion by the H2-receptor antagonists. This is of no clinical importance in short term treatment, but long term use of H2-receptor antagonists may theoretically contribute to the occurrence of iron or cobalamin deficiency anaemia.
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PMID:Haematological adverse effects of histamine H2-receptor antagonists. 290 59

Histamine2-blockers are being used more extensively in the pediatric short gut patient as an agent to accelerate small bowel adaptation. Reversal of lipid malabsorption and a direct trophic effect on the intestinal crypt cells have been postulated as the mechanism for the salutary influence of cimetidine. Weanling Sprague-Dawley rats underwent 85% small bowel resection. Controls had repair of a simple ileal transection. Rats received either a fat-defined rat chow only, or chow with high- or low-dose cimetidine, 2% cholestyramine, or cholestyramine/low-dose cimetidine. All animals were killed 2 weeks postresection, and ileal and jejunal sections were examined for changes in villous and crypt morphology. The animals receiving cimetidine showed earlier and more consistent weight gain than resected animals who received no adjunctive treatment. High- and low-dose regimens were equally efficacious. Cimetidine administered alone decreased fecal fat losses, but not when given with cholestyramine. The cimetidine/cholestyramine group showed increased weight gain when referenced to the resection controls despite continuing lipid malabsorption. Villous and crypt lengthening did not correlate with clinical evidence of adaptation. An augmented lymphocytic activity (plasma cell hyperplasia, enlargement Peyer's patches) was present in the hyperplastic ileal segments of the cimetidine-treated rats. Overall immunoreactivity was similar in all study groups. No significant differences in villous morphology or immunologic activity were seen in jejunal segments. The effects of H2-blockers on lipid absorption and intestinal hyperplasia are inadequate to explain the benefits of cimetidine in the short gut patient. Examination of the immunology of the short bowel complex merits further attention in elucidating cimetidine's action in this setting.
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PMID:Cimetidine and neonatal small bowel adaptation: an experimental study. 361 36

Twenty patients with exocrine pancreatic insufficiency secondary to alcohol abuse were studied for the presence of bile salt malabsorption. Fecal bile salts and fecal fat excretion were determined in 15 patients receiving pancreatic enzyme therapy, not receiving enzyme therapy, and on a regimen of pancreatic enzymes plus cimetidine. Serum bile salt levels were measured during fasting and postprandial conditions both during enzyme therapy and after it was stopped in 8 cases. In addition, 5 patients underwent [14C]cholylglycine breath testing during and after discontinuation of enzyme therapy. The fecal bile salt excretion varied between 610 and 3460 mg/day in the untreated patients. Treatment with pancreatic enzymes was associated with significant (p less than 0.05) reduction in fecal bile salt and fecal fat excretion. Cimetidine therapy in addition to enzyme therapy further reduced steatorrhea but failed to alter bile salt excretion significantly. Serum cholylglycine level showed significant (p less than 0.05) postprandial increase in patients receiving enzyme therapy, suggesting improved bile salt absorption. These data suggest a wide range of bile salt malabsorption in alcoholic patients with pancreatic insufficiency, which improves with pancreatic enzyme therapy.
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PMID:Bile salt malabsorption in pancreatic insufficiency secondary to alcoholic pancreatitis. 375 16

Small (1-4 mm) hexagonal filling defects were found on air-contrast studies of the duodenal bulb in three patients with unresponsive (atypical) celiac disease. Multiple biopsies confirmed both celiac disease and peptic duodenitis. Stimulated acid outputs determined in two patients were in the peptic ulcer range. Cimetidine therapy led to improved absorption in all three patients. Repeat upper gastrointestinal series and endoscopy in one patient showed no evidence of nodularity or peptic duodenitis, indicating that these changes may be reversible. Peptic disease may contribute to nodularity in the duodenal bulb and relative lack of response to a gluten-free diet of some patients with celiac disease. The finding of tiny nodules in the duodenal bulb in a patient with malabsorption should lead to consideration of celiac disease as a primary diagnosis with peptic duodenitis as an aggravating factor.
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PMID:"Bubbly" duodenal bulb in celiac disease: radiologic-pathologic correlation. 660 44

The suppressive effects of cimetidine on acid, pepsin, and intrinsic factor secretion have been well documented; however, the effect of cimetidine on cobalamin absorption has not been assessed. The absorption of both unbound [57Co]cyanocobalamin and protein-bound [57Co]cyanocobalamin was evaluated in 12 patients with duodenal ulcer disease during and after discontinuation of cimetidine therapy. Cimetidine administration did not lead to malabsorption of unbound cobalamin but caused malabsorption of protein-bound cobalamin (0.22 +/- 0.08%, [mean +/- 1 SEM] versus 2.3 +/- 0.10% in control subjects, P less than 0.01). This malabsorption was reversible upon discontinuation of cimetidine. Patients on cimetidine therapy malabsorb protein-bound cobalamin and, during long-term treatment, are at risk for developing cobalamin deficiency. This malabsorption was reversible upon discontinuation of cimetidine. Patients on cimetidine therapy malabsorb protein-bound cobalamin and, during long-term treatment, are at risk for developing cobalamin deficiency. This malabsorption of protein-bound cobalamin is not detectable by the usual tests of cobalamin absorption which employ unbound cobalamin.
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PMID:Malabsorption of protein-bound cobalamin but not unbound cobalamin during cimetidine administration. 676 34

Some patients with cystic fibrosis (CF) have malabsorption of fat and protein in spite of large amounts of supplemental pancreatic enzymes. This is partly due to acid inactivation of exogenous pancreatic enzymes in the stomach. The effect of cimetidine on gastric function and exogenous pancreatic enzymes was assessed by a marker perfusion technique in 4 CF children in a double-blind controlled fashion. Gastric acid secretion was higher in CF patients than in controls (P less than 0.005) and was reduced significantly by oral cimetidine (P less than 0.02). Rapid inactivation of exogenous trypsin and lipase occurred when gastric pH fell to less than 4.5. There was no loss of enzyme activity during treatment with cimetidine when gastric pH remained above 5.5. Activity of lipase and trypsin in the jejunum improved in all subjects. Fat and nitrogen absorption assessed by a balance technique during the study period showed a small improvement in fat absorption while on cimetidine. We conclude that some CF patients have a high meal-stimulated gastric acid output which causes inactivation of trypsin and lipase. Cimetidine was effective in reducing acid secretion in such patients and led to small improvements in fat absorption.
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PMID:The effect of cimetidine on meal-stimulated gastric function and exogenous pancreatic enzymes in cystic fibrosis. 692 76