Anti helicobacter pylori: amoxicillin, clarithromycin etc
.Histamine antagonists inhibit the action of histamine on the acid-producing cells of the stomach and reduce stomach acid
SIDE EFFECTS ; it include constipation , diarrhea, fatigue , headache, insomnia, muscle pain, and vomiting. Major side effects include confusion and hallucinations, gynacomastia (enlargement of the breasts); impotence.
Proton pump inhibitors act by irreversibly blocking the hydrogen/potassium adenosine triphosphatase enzyme system of the gastric parietal cells.
The proton pump is the terminal stage in gastric acid secretion
PROTON PUMP INHIBITORS
Omeprazole is inactive at neutral pH, but at pH<5 rearranges to two charged cationic forms(a sulphenic acid and a sulphenamide configurations)that react covalently with SH groups of the H + K + ATPase enzyme and inactivate it irreversibly, especially when two molecules of omeprazole react with one molecule of the enzyme
SIDE EFFECTS Stomach pain, Diarrhea,Constipation,Dizziness,Pain,Hives, Itching,seizures
ACETYL CHOLINE ANTAGONIST
It selectively block M1 muscaranic recptors and inhibits gastric secretion.
Because of their relatively poor efficacy, side effects, and risk of blood disorders, they are rarely used today
AGENTS THAT ENHANCE MUCOSAL DEFENSE
prostaglandins are produced in the gastric
mucosa and appear to serve a protective role by inhibiting acid secretion and promoting mucus
and bicarbonate secretion.
In addition, PGs inhibits gastrin production, increase mucosal blood flow and probably have an ill defined cytoprotective action.
DRUGS : Misoprostol
Misoprostol acts upon gastric parietal cells , inhibiting the secretion of gastric acid via G-protein coupled receptor-mediated inhibition of adenylate cyclase , which leads to decreased intracellular cyclic AMP levels and decreased
pump activity at the apical surface of the parietal cell
Other common side effects include: abdominal pain, nausea, flatulence, headache, dyspepsia, vomiting, and constipation.
Sucralfate is a locally acting substance that in an acidic environment (pH < 4), reacts with hydrochloric acid in the stomach to form a cross-linking, viscous , paste-like material capable of acting as an acid buffer for as long as 6 to 8 hours after a single dose . It also attaches to proteins on the surface of ulcers, such as albumin and fibrinogen , to form stable insoluble complexes. These complexes serve as protective barriers at the ulcer surface, preventing further damage from acid , pepsin , and bile .
The most common side effects seen are constipation . Less commonly reported include flatulence, cephalalgia (headache), xerostomia (dry mouth).
It is used in treatment of
SODIUM BICARBONATE (ANTACID)
It is water soluble, acts instantaneously, but duration of action is short. It is a potent neutralizer , pH may raises above 7.
It causes systemic alkalosis, gastric distention, rebound acidity and milk-alkali syndrome
It is restricted to casual treatment of heartburn and to treat acidosis
ANTI H.PYLORI DRUGS
Anti microbials that have been found clinically effective against H.pylori are: amoxicillin, clarithromycin, tetracycline and metronidazole.
A combination regimen is preferred, using gastric acid inhibitors and antibiotics.
A proton pump inhibitor or H2 blocker + amoxicillin + clarithromycin or metronidazole