Antacids, H2 antagonists & PPIs. - Antacids & Alginates

Mutliple Choice Question

Indication

Antacids are the simplest therapy for symptoms of dyspepsia. In small doses, antacids relive pain, but are not a cure for peptic ulcers. Antacids can heal ulcers in large doses, however this is not practical, as large frequent doses which would make compliance difficult, and result in high incidence of adverse effects.

Mutliple Choice Question

Adverse effects

In 1912, Sippy introduced a milk and antacid treatment for peptic ulcer. This contained calcium carbonate, sodium bicarbonate, magnesium oxide, and bismuth subcarbonate¹. Although this provided relief for symptomatic peptic ulcers, patients who were took this long term, started developing hypercalcemia, alkalosis and renal failure-known as milk alkali syndrome.

Sodium bicarbonate is readily absorbed from the GI tract, and can result in systemic alkalosis, resulting in the hypercalcemia, nephrocalcinosis and renal failure associated with the milk alkali syndrome. Calcium salts taken in excess can also lead to hypercalcemia, and result in the milk alkali syndrome.

Magnesium and Aluminium salts are less readily absorbed. Therefore, their effects are mainly on the bowel. What effect do you think would Mg salts tend to have on the bowel?

Diarrhoea
Constipation

Ephemera Collection.
QV: Blotters: Allen & Hansbury, 1904-1909.

Image: Wellcome Collection

Interactions

Antacids can reduce absorption of various drugs, and therefore should not be taken at the same time. For a complete list of drug interaction, please refer to the BNF.