Stomach Tablet (Caco3, Mgco3, Nahco3, Belladona. Atropine Methyl Nitrate) MOA OF BELLADONA: It blocks the muscarinic effect of endogenous as well as externally administered acetylcholine by competiting with acetylcholine for muscarinic receptor at cholinergic nerve endings. MOA OF ATROPINE ON GASTRIC SECRETION: It can reduce the volume and total acidity of gastric secretion. The secretion of acid without any food in stomach reduces the secretion of mucin and enzymes in gastric juice and also blocks the gastric secretion elicited by parasympathomimetic agents. PHARMACOKINETICS: Belladona is satisfactorily absorbed from GI tract, from mucus membrane. Atropine is partly detoxified in liver and partly excreted unchanged by kidneys. USES: As an antispasmodic, colitis, peptic ulcer.