calcium carbonate: clinical use

Prescribing considerations

• Confirm that recurrent or persistent symptoms are not masking significant gastrointestinal disease.
• Avoid prolonged or excessive use, particularly in renal impairment or alongside high dietary or supplemental calcium intake.
• Review prescribed, non-prescribed and nutritional products for calcium-related absorption interactions.
• Consider product excipients and the patient's ability to chew, suck or safely use medicated gum.

Contraindications and cautions

• Hypersensitivity to calcium carbonate or product excipients.
• Hypercalcaemia or a condition causing hypercalcaemia.
• Calcium-containing renal calculi; avoid in hypercalciuria.
• Severe renal insufficiency.
• Hypophosphataemia.
• For the selected gum, hereditary fructose intolerance because it contains sorbitol and isomalt.

Monitoring

• Monitor plasma calcium and phosphate if used in mild-to-moderate renal impairment.
• Monitor serum calcium during concomitant thiazide treatment.
• Assess for hypercalcaemia, alkalosis and renal dysfunction if excessive or prolonged exposure is suspected.

Clinical pharmacology

A locally acting antacid that neutralises gastric hydrochloric acid. A small proportion of calcium is absorbed and normally cleared renally; impaired renal function can increase calcium concentrations.

Formulation and product differences

• The selected chewable tablet contains sucrose and is unsuitable for certain hereditary sugar-intolerance disorders.
• The selected medicated gum contains sorbitol and isomalt, is sugar-free, and its residue should not be swallowed.
• Elemental calcium content and excipients differ between products; brands and formulations are not automatically interchangeable.

Chewable tablet

Route: Oral

Strengths: 500 mg, 1500 mg

Medicated chewing gum

Route: Oromucosal

Strengths: 750 mg