I. Antacids
II. Antacids with laxative action
III. Anti-dyspeptic & Carminatives
ANTACIDS: -
Definition: Antacids arc the mostly used in acute hyperacidity & associated pain. Antacid preparations are weakly basic and consist of metal salts, most commonly aluminum hydroxide, magnesium hydroxide, calcium carbonate, or sodium bicarbonate.
Classification: Antacids are classified as:
a. Systemic antacids: Those are usually absorbed from the gut to the system and preferably act as blood alkalizer to combat acidosis rather than antacids, such as, sodium bicarbonate, sodium citrate, sodium acetate, potassium citrate.
b. Locally acting antacids: These are not significantly absorbed from the gut and mainly used as antacids such as aluminum hydroxide, magnesium hydroxide, magnesium tri-silicate.
ALUMINIUM & MAGNESIUM
ALUMINIUM & MAGNESIUM (Tablet/Suspension)
Introduction: Aluminum & magnesium antacid preparations are non-systemic antacids. These drugs are minimally absorbed from the gut and so, mainly used as antacids such as aluminum hydroxide, magnesium hydroxide, and magnesium tri-silicate.
How it acts: When antacids are ingested per oral these salts dissociate to neutralize gastric acid and form neutral salts within the stomach. Thus, the aim of using antacid is to increase the pH of gastric contents to a range of 3.5 to 4.5 at which pepsin activity is greatly diminished. Pain usually occurs when pH is below 3.5. There is good evidence from the clinical trials that antacids do not accelerate the rate of healing in gastric ulcer. but in duodenal ulcer, where very high doses of antacids such as 200-300ml of aluminium hydroxide daily in divided doses at frequent intervals well promote ulcer healing, but such treatment is inconvenient to the patient.
When to use: Hyperacidity, gastric & duodenal ulcer, gastritis, heartburn, dyspepsia, gastro-esophageal reflux disease, flatulence.
When must not to use: Hypophosphataemia (if simethicone is added), renal failure, severely debilitated patients, 1st trimester of pregnancy.
Probable Adverse effects: Diarrhoea, constipation, nausea, vomiting.
Cautions: Renal dysfunction, low phosphate diet, prolonged use.
Dosage: See below under individual preparations.