Famotidine

What it is

Famotidine is an H2 blocker: it blocks histamine receptors on the acid-secreting cells of the stomach, so less acid is produced. The effect is milder and shorter than that of a proton pump inhibitor but comes on quickly. It is used for heartburn and acid-related stomach discomfort.

Used for

• Heartburn

What to know while taking it

It can be taken with or without food, and it is often used ahead of a meal or at bedtime, when acid-related symptoms tend to appear. Because it lowers stomach acid, it can interfere with the release of vitamin B12 from food, which matters mainly with prolonged use. Reduced acid can likewise blunt the absorption of drugs and supplements that need an acid stomach, so spacing them apart is sensible.

When to see a doctor

Heartburn that does not settle, returns as soon as treatment stops, or comes with trouble swallowing, vomiting, black stools or weight loss should be seen by a doctor.

Nutrients affected

• vitaminB12 — absorption blocked with (Hemoglobin, Homocysteine, Mean cell volume (MCV))