Antacids do not prevent the overproduction of acids. Their work is limited to the neutralisation of the acidic pH in the stomach. They provide symptomatic relief in dyspepsia, peptic ulceration and gastroesophageal reflux disease.
- Al3+ salts
- Mg2+ salts
- Ca2+ salts
- sodium bicarbonate
Antacids are OTCs which can be found as chewing tablets, powder and gel formulations. They provide relief generally within 5–15 minutes of administration and should be administered between meals and at bedtime (relief duration ranges from 1 hour to 3 hours).
 Side effects of antacids
- Na-bicarbonate can cause alkalosis, which gives an unpleasant taste in the mouth. Na-bicarbonate is very hydrosoluble, is frequently used and has a quick onset of action with a short duration of action. Na+ can also cause problems in hypertensive patients, in people with renal failure and in patients with cardiac problems
- Ca2+ salts can cause hypercalcemia and interfere with the absorption of other drugs including Ca2+ itself
- Ca2+ salts can cause kidney stones
- CaCO3 produces gas and causes belching and flatulence, which is why antacids are combined with antiflatulents like simethicone or activated charcoal
- Constipation: antacids interfere with peristalsis and Al3+ salts cause constipation (so Al3+ salts can be used to treat diarrhoea)
- Mg2+ salts cause diarrhea and are also used as laxatives
- When used in long-term therapy, antacids can increase GI secretion via a compensatory mechanism which is termed the rebound effect.
|Heartburn/Gastritis/Gastric ulcer/Duodenal ulcer/Gastroesophageal reflux|
|H2 antagonists||Famotidine • Nizatidine • Ranitidine (Zantac)|
|Proton-pump inhibitors||Dexlansoprazole (Dexilant) • Esomeprazole (Nexium) • Lansoprazole (Prevacid) • Omeprazole (Losec, Prilosec) • Omeprazole/Sodium bicarbonate (Zegerid) • Pantoprazole (Controloc, Pantecta, Pantoloc, Protonix) ( • Rabeprazole (Aciphex, Pariet)|
|Other drugs||Alginic acid • Magaldrate • Sucralfate|
|Combination Regimens||Bismuth Subcitrate Potassium/Metronidazole/Tetracycline (Pylera) • Lansoprazole/Amoxicillin/Clarithromycin (Prevpac)|