Biochem/Physiol Actions | Cimetidine is a histamine H2-receptor antagonist. It reduces basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin. It is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Cimetidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Cimetidine include an increase in gastric bacterial flora such as nitrate-reducing organisms. Cimetidine is a histamine H(2)-receptor antagonist. Enhancing anti-tumor cell-mediated responses, cimetidine blocks histamine's ability to stimulate suppressor T lymphocyte activity and to inhibit natural killer (NK) cell activity and interleukin-2 production. Cimetidine also may inhibit tumor growth by suppressing histamine's growth-factor activity and blocking histamine-induced stimulation of vascular endothelial growth factor (VEGF), a pro-angiogenic growth factor. |
