Tums (Calcium Carbonate) Dosage and Usage for Heartburn and Indigestion
Recommended Dosage
For adults and children 12 years and older, chew and swallow 1-2 tablets every 2-4 hours as needed, not exceeding 5 tablets in 24 hours. 1
- Do not use the maximum dosage for more than 2 weeks without physician supervision 1
- Children under 12 years should consult a doctor before use 1
- Constipation may occur as a common side effect 1
Role in GERD Management
Calcium carbonate antacids like Tums are most appropriately used for rapid, on-demand relief of heartburn symptoms, but are inferior to H2-receptor antagonists and proton pump inhibitors for sustained symptom control. 2
When Antacids Are Appropriate:
- Antacids are the most rapidly acting agents for heartburn relief, making them ideal for on-demand therapy when patients take medication only in response to symptoms 2
- The American Gastroenterological Association recommends combining antacids with an H2RA or PPI to sustain their efficacy 2
- Antacids work primarily in the lower esophagus rather than the stomach, which is their main site of action for heartburn relief 3
Limitations Compared to Other Therapies:
- Proton pump inhibitors are more effective than H2-receptor antagonists, which are more effective than antacids alone for treating esophageal GERD syndromes 2
- Calcium carbonate provides only temporary symptom relief and does not heal esophagitis as effectively as acid-suppressive therapy 4
- Studies show calcium carbonate may cause "acid rebound" where gastric pH remains at or below baseline values after the initial neutralizing effect wears off 3
Mechanism and Onset of Action
Calcium carbonate neutralizes esophageal acid rapidly and may improve esophageal motility through calcium's effects on muscle contractility. 5
- Calcium released from chewed antacids significantly increases proximal esophageal contractile amplitude and improves acid clearance 5
- The duration of action in the esophagus is approximately 60 minutes 3
- Onset of symptom relief occurs within minutes, faster than H2-receptor antagonists but variable compared to aluminum/magnesium hydroxide formulations 3
Important Caveats and Pitfalls
Calcium Carbonate Characteristics:
- Calcium carbonate contains 40% elemental calcium (e.g., TUMS EX 750mg provides 300mg elemental calcium, TUMS Ultra 1000mg provides 400mg elemental calcium) 2
- Requires gastric acid for absorption and must be taken with meals 6, 7
- For patients on proton pump inhibitors or with achlorhydria, calcium citrate is strongly preferred over calcium carbonate as it does not require gastric acid for absorption 6, 7
Safety Considerations:
- Do not exceed 2,000-2,500 mg total daily calcium intake from all sources (food and supplements combined) due to increased risk of kidney stones and potential cardiovascular events 6, 8
- When using Tums for both heartburn relief and calcium supplementation, account for total elemental calcium intake to avoid exceeding safe limits 8
- Constipation and bloating are common side effects of calcium carbonate supplementation 8, 1
Clinical Strategy:
- For chronic heartburn (more than twice weekly), empirical therapy with a PPI once daily is more appropriate than relying on antacids alone 2
- If symptoms persist on once-daily PPI, escalate to twice-daily PPI dosing before considering treatment failure 2
- Reserve antacids for breakthrough symptoms or rapid relief while waiting for acid-suppressive therapy to take effect 2