calcium carbonate + light magnesium carbonate + sodium hydrogen carbonate: clinical use

Prescribing considerations

• Investigate recurrent or persistent symptoms where another cause is possible.
• Avoid during the first three months of pregnancy; use caution later in pregnancy.
• Review concurrent oral medicines because antacids may reduce absorption.
• The selected product contains sugar and peppermint oil; consider excipient intolerance.

Contraindications and cautions

• Hypophosphataemia
• Renal failure
• Heart failure

Monitoring

• No routine laboratory monitoring is specified for occasional use.
• Review persistent symptoms and troublesome constipation or diarrhoea.
• For suspected excessive exposure, consider calcium, magnesium or sodium disturbances.

Clinical pharmacology

The alkaline salts neutralise gastric hydrochloric acid. Some calcium and magnesium are absorbed. Absorbed magnesium is normally eliminated in urine, while much of the calcium is excreted in faeces. Unreacted bicarbonate may be absorbed and excreted in urine.

Formulation and product differences

• The selected formulation is a chewable tablet for oral use.
• It contains sugar, soluble saccharin, maize starch, calcium stearate and peppermint oil.
• It is described as essentially sodium-free because it contains less than 1 mmol sodium per tablet.
• The selected product is classified as General Sales List.