H2 blockerAcid reducer
Famotidine
Tablet
Quick Summary
Famotidine blocks histamine in the stomach, which lowers acid production. It works more quickly than PPIs but is less strong.
Heartburn and indigestion
Stomach ulcers
Medical Uses
Heartburn and indigestion: Short-term relief.
Stomach ulcers: Treatment and prevention.
How it's taken
Taken once or twice a day, or before meals that trigger symptoms.
Your doctor decides the right dose for you and how long to take it.
Your doctor decides the right dose for you. Follow their instructions and the label.
Common Side Effects
Headache
Sometimes.
Dizziness
Rarely.
Constipation or diarrhoea
Sometimes.
Interactions
Some antifungals
Need stomach acid to be absorbed.
Critical Warnings
Warning signs
Black Box Warning: Difficulty swallowing, vomiting blood or black stools need urgent care.
Kidney problems
Dose may need adjusting.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Famotidine: drug information(opens in a new tab) · MedlinePlus, US National Library of Medicine