How Indigestion Remedies Work: Antacids, PPIs, and More

Over-the-counter indigestion tablets act via different mechanisms:

• Antacids (calcium carbonate, magnesium hydroxide, aluminum hydroxide): Neutralize existing gastric acid → rapid, short-lived relief. May cause constipation (Al, Ca) or diarrhea (Mg).
• H₂-receptor antagonists (famotidine, cimetidine): Block histamine-stimulated acid secretion → onset 30–60 min, duration 6–12 hrs.
• Proton pump inhibitors (PPIs) (omeprazole, esomeprazole, lansoprazole): Irreversibly inhibit H⁺/K⁺-ATPase on parietal cells → profound, long-lasting acid suppression. Best taken 30 min before breakfast. Full effect in 2–4 days.
• Alginate raft-formers (Gaviscon): Create buoyant gel barrier on gastric contents → prevent reflux.
• Simethicone: Coalesces gas bubbles → relieves bloating.
• Digestive enzymes (lactase, pancrelipase): Aid specific maldigestion.

Important: These treat symptoms, not underlying causes (GERD, ulcer, H. pylori, gastroparesis, malignancy). Persistent/alarm symptoms (weight loss, dysphagia, bleeding, anemia) require medical evaluation.