Cimetidine
Tagamet (cimetidine) is an H2 receptor antagonist that reduces stomach acid production. It is commonly prescribed to treat peptic ulcers, gastroesophageal reflux disease (GERD), and conditions where excess stomach acid causes discomfort such as heartburn and indigestion. As one of the first FDA-approved acid-reducing medications, it has been used safely for decades in appropriate patients.
Tagamet is an acid-reducing medication used to treat ulcers, GERD, and heartburn by blocking histamine receptors in the stomach.
Key facts at a glance
- RxNorm
- 152402
- Generic
- Tagamet
- Class
- brand-name
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- —
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Tagamet is used to treat and prevent peptic ulcers (both gastric and duodenal), manage gastroesophageal reflux disease (GERD), alleviate heartburn, and treat conditions where the stomach produces excessive acid. It may also be used as part of combination therapy for certain infections.
Tagamet works by blocking histamine H2 receptors on stomach cells called parietal cells. This action significantly reduces the production of stomach acid (hydrochloric acid), creating a less acidic environment that allows ulcers to heal and relieves symptoms caused by excess acid.
Tagamet may interact with several medications including blood thinners, certain antidepressants, and some heart medications by affecting their metabolism. It should be used with caution in patients with kidney or liver impairment. Common side effects include headache, dizziness, and diarrhea. Patients should avoid taking Tagamet within 2 hours of other medications as it can affect their absorption.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 9, 2026. · Read our editorial policy