Cimetidine Hydrochloride
Cimetidine Hydrochloride is an H2 receptor antagonist that reduces stomach acid production by blocking histamine signals in the stomach lining. It is used to treat conditions involving excess gastric acid such as peptic ulcers, gastroesophageal reflux disease (GERD), and heartburn. While effective, it has largely been replaced by newer acid-reducing medications due to a higher risk of drug interactions and side effects.
Cimetidine Hydrochloride is an acid-reducing medication used to treat ulcers, GERD, and heartburn by blocking stomach acid production.
Key facts at a glance
- RxNorm
- 91251
- Generic
- Cimetidine Hydrochloride
- Class
- pin-variant
- 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.
Treatment and prevention of peptic ulcers (gastric and duodenal), gastroesophageal reflux disease (GERD), heartburn, and conditions where reduction of gastric acid is beneficial such as Zollinger-Ellison syndrome.
Acts as a competitive antagonist at histamine H2 receptors on gastric parietal cells, blocking histamine-mediated stimulation of acid secretion and thereby reducing the volume and acidity of gastric juice.
May interact with numerous drugs by inhibiting cytochrome P450 enzymes; caution advised with warfarin, theophylline, phenytoin, and many others. Has antiandrogenic effects and may cause gynecomastia. Generally reserved for patients who cannot tolerate newer acid-suppressing agents. Use with caution in patients with impaired renal or hepatic function.
Official drug label
WellAlly may earn a referral fee from linked resources at no extra cost to you. Editorial content is never influenced by commercial relationships.
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 25, 2026. · Read our editorial policy