famotidine at a glance
Medicine class
Histamine H2-receptor antagonist (acid-suppressing medicine).
Licensed uses
Ulcers, prevention of recurrent duodenal ulceration, reflux oesophagitis and Zollinger–Ellison syndrome.
Food
The tablets may be taken with or without food.
Kidney function
Famotidine is mainly cleared by the kidneys, so impaired kidney function requires additional prescribing care.
What is famotidine used for?
The selected UK product is licensed for acid-related conditions in adults.
Duodenal ulcers and prevention of their recurrence.
Benign gastric ulcers.
Mild to moderate reflux oesophagitis.
Zollinger–Ellison syndrome, a rare condition causing excessive stomach-acid production.
How does famotidine work?
Famotidine blocks histamine H2 receptors on acid-producing stomach cells, reducing the volume and acidity of gastric secretions and lowering pepsin secretion.
famotidine preparations and strengths
Tablet
Route: Oral
Strengths: 20 mg, 40 mg
How to take famotidine
Take famotidine by mouth as prescribed. It may be taken with or without food. The selected tablet's score line helps with swallowing but does not divide it into equal amounts.
Swallow with liquid.
Check with a pharmacist before using antacids or sucralfate because they can reduce famotidine absorption.
Do not stop treatment for long-standing ulcer disease abruptly without discussing it with the prescriber.
famotidine side effects
Common or expected effects
- Headache
- Dizziness
- Constipation
- Diarrhoea
Get urgent medical advice
- Severe allergic reaction, including swelling, wheezing or difficulty breathing
- Severe blistering or peeling skin reactions
- Unexplained breathlessness or persistent dry cough suggesting lung inflammation
- Unusual infections, fever, bruising or bleeding suggesting a blood-cell disorder
- Yellow skin or eyes, which may indicate liver injury
- Seizures, severe confusion or an abnormal heartbeat, particularly with impaired kidney function
famotidine in pregnancy
Use in pregnancy only when the prescriber considers it clearly necessary. UK pregnancy information reports no clear evidence that H2-receptor antagonists harm the baby, although another acid-suppressing medicine may usually be considered first. Discuss use with a doctor, midwife or pharmacist.
famotidine while breastfeeding
Famotidine enters breast milk. UK Specialist Pharmacy Service guidance states that it can be used while breastfeeding a full-term, healthy infant because only very small amounts enter milk. Monitor the infant as advised and seek specialist input for premature or unwell infants.
famotidine interactions
By raising stomach pH or affecting absorption and elimination, famotidine can alter some medicines' exposure or effectiveness.
Atazanavir
Reduced stomach acidity may lower its absorption and effectiveness.
Ketoconazole and itraconazole
Famotidine may reduce absorption of these antifungals; ask a pharmacist about administration timing.
Posaconazole oral suspension
Absorption may be reduced, so combined use should be avoided where possible.
Dasatinib, erlotinib, gefitinib and pazopanib
Common questions about famotidine
Answers are fully visible for fast scanning and source review.
Can famotidine be taken with food?
Yes. The selected tablets may be taken with or without food.
Can famotidine tablets be split?
The selected tablet may be broken for easier swallowing, but its score line does not produce equal portions.
How quickly does famotidine start reducing stomach acid?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.