[Cimetidine. Clinical pharmacology and toxicity (author's transl)].

Cimetidine, a new histamine H2-receptor antagonist (H.H2.R.A.) is a potent inhibitor of basal and stimulated gastric acid secretion. Contrary to anticholinergics, it does not affect gastric emptying nor does it decrease lower oesophageal sphincter pressure; cimetidine may therefore be used as the treatment of reflux oesophagitis. After prolonged administration of currently used therapeutic doses, basal and post-prandial serum gastrin levels remain unchanged and the parietal cell mass is not increases. Cimetidine toxicity is very low. Cimetidine is effective in promoting healing and pain relief of gastric and duodenal ulcer. In the latter long-term treatment for prevention of relapse is efficient, but the appraisal of its safety remains debated. Efficiency of H.H2.R.A. in the prophylaxis of gastrointestinal haemorrhage in patients with fulminant hepatic failure has been proven. Furthermore, cimetidine has a dramatic ability to control haemorrhage from acute erosive lesions in any seriously-ill patient. It may also be of benefit in the treatment of bleeding from gastric or duodenal ulcer and, whatewer the lesion, in the prevention of bleeding recurrence. In the Zollinger-Ellison syndrome, good results have been obtained but cimetidine treatment must be decided and supervised only by well-informed specialists. Lastly, in patients with severe exocrine pancreatic insufficiency, cimetidine prevents gastric degradation of orally administered pancreatic extracts and decreases steatorrhea.