What it is used for

Heartburn and acid reflux
Healing and preventing stomach and duodenal ulcers

Read our guides:

Acid reflux (GORD)

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Some allergic conditions, together with an antihistamine

How it works

Famotidine blocks histamine H2 receptors on the stomach lining. Histamine normally tells the stomach to release acid, so blocking it reduces acid.

Side effects

Like all medicines, Famotidine can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

headache
dizziness
constipation or diarrhoea

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

a fast or irregular heartbeat
confusion, especially in older people or people with kidney problems
yellowing of the skin or eyes

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

People with kidney problems may need a lower dose.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.