Cimetidine
Cimetidine 400MG
What is Cimetidine?
Cimetidine is a medication used to treat conditions like ulcers and gastroesophageal reflux disease (GERD), which causes heartburn. It helps reduce the amount of acid produced in the stomach.Side Effects
- Unexplained fever, unusual bruising.
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Bloody or black, tarry stools.
Warnings
- Make sure your doctor knows if you are pregnant or breast feeding.
- Tell your doctor if you have a history of heart disease, kidney disease, or liver disease.
- Make sure your doctor knows if you have painful heartburn that also causes dizziness, sweating, chest or shoulder pain, trouble breathing, or trouble swallowing. Tell your doctor if you have unexpectedly lost weight.
- Avoid using this medicine if you are vomiting. Avoid smoking tobacco while you are using cimetidine. Smoking may cause the medicine to not work properly.
- If you have had ongoing heartburn for 3 months or longer, you may have a serious medical problem. Stop using this medicine and call your doctor.
Prescription savings · · · ·
What is Cimetidine ?
Cimetidine is a medication used to treat conditions like ulcers and gastroesophageal reflux disease (GERD), which causes heartburn. It helps reduce the amount of acid produced in the stomach.- Unexplained fever, unusual bruising.
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Bloody or black, tarry stools.
- Pain when you swallow.
- Vomiting blood or material that looks like coffee grounds.
- Yellowing of your skin or the whites of your eyes.
- Make sure your doctor knows if you are pregnant or breast feeding.
- Tell your doctor if you have a history of heart disease, kidney disease, or liver disease.
- Make sure your doctor knows if you have painful heartburn that also causes dizziness, sweating, chest or shoulder pain, trouble breathing, or trouble swallowing. Tell your doctor if you have unexpectedly lost weight.
- Avoid using this medicine if you are vomiting. Avoid smoking tobacco while you are using cimetidine. Smoking may cause the medicine to not work properly.
- If you have had ongoing heartburn for 3 months or longer, you may have a serious medical problem. Stop using this medicine and call your doctor.
- Unexplained fever, unusual bruising.
Cimetidine Coupons & Prices
Cimetidine 400MG
Weight-loss medication, prescribed online
Licensed U.S. providers · No insurance needed · Shipped to your door
Looking for a cimetidine coupon? Cimetidine is the generic form of Tagamet, a histamine H2-receptor blocker used to treat and prevent stomach and duodenal ulcers, erosive GERD, and other acid-related conditions. Because it is a generic, cimetidine is already one of the lower-cost H2 blockers, but the cash price can still vary a lot from one pharmacy to the next. Enter your ZIP above to compare today's cimetidine price across more than 60,000 U.S. pharmacies and print or show a free Rx.com discount coupon at the counter.
What is cimetidine and how does it work?
Cimetidine is a histamine H2-receptor antagonist, commonly called an H2 blocker. It works by blocking histamine's signal to the acid-producing cells in the stomach lining, which lowers the amount of acid the stomach makes. Less acid gives ulcers and irritated tissue a chance to heal and eases acid-related symptoms.
Prescription cimetidine is FDA-approved for short-term treatment of active duodenal ulcers and active benign gastric ulcers, for maintenance therapy of duodenal ulcer at a reduced dose after healing, for erosive GERD, and for pathological hypersecretory conditions such as Zollinger-Ellison syndrome. An injectable form is used to help prevent upper GI bleeding in critically ill patients. Over-the-counter Tagamet HB 200 is used to relieve and prevent heartburn from acid indigestion and sour stomach. Your prescriber can tell you whether cimetidine is the right fit for your situation.
Cimetidine cost without insurance and how to save
Cimetidine is available as a generic, which is why it is generally an affordable H2 blocker even if you pay cash. Still, pharmacies set their own cash prices, so the amount you would pay without insurance can differ widely between two stores in the same town. That is exactly why comparing matters. Rx.com checks cimetidine prices across more than 60,000 pharmacies so you can find the lowest one near you.
To see what cimetidine costs today, enter your ZIP code above. You will get current cash prices at nearby pharmacies along with a free Rx.com discount coupon you can use whether or not you have insurance. There is no manufacturer copay card for generic cimetidine; the savings here come from comparing pharmacy cash prices and using the free coupon. The brand version is sold as Tagamet, with Tagamet HB available over the counter.
Cimetidine vs. other H2 blockers and acid reducers
Cimetidine is one of several acid-reducing options, and the right choice depends on your history and other medications. The main practical difference is that cimetidine is a strong inhibitor of liver CYP450 enzymes, so it interacts with more drugs than newer H2 blockers do. For many people, a prescriber may prefer an alternative with fewer interactions.
- Famotidine (Pepcid) and nizatidine are other H2 blockers with far fewer drug interactions. Nizatidine is available as a generic capsule; the branded Axid and the oral solution have been discontinued.
- Omeprazole and pantoprazole are proton pump inhibitors, a different class that reduces acid more strongly for conditions like erosive GERD.
You may remember ranitidine (Zantac), an H2 blocker that was once widely used. It is no longer an option: in April 2020 the FDA requested that all ranitidine products be pulled from the U.S. market because of NDMA, a probable human carcinogen, that could build up in the drug over time. Ranitidine is not available by prescription or over the counter, so it is not something to compare or switch to today.
Talk with your doctor or pharmacist about which acid reducer fits your needs, and compare prices for the available options on Rx.com to see which is most affordable near you.
Cimetidine safety and side effects
Cimetidine has no boxed warning, but there are important points to know. Reversible confusion, agitation, and hallucinations can occur, mostly in older adults, people who are severely ill, or those with reduced kidney function; the dose should be lowered in kidney impairment. Because cimetidine strongly inhibits liver CYP450 enzymes (including CYP1A2, CYP2D6, and CYP3A4), it has extensive drug interactions and can raise blood levels of medications such as warfarin, phenytoin, and theophylline. High-dose or long-term use can cause breast enlargement in men (gynecomastia) and, rarely, impotence, reflecting its antiandrogenic effects. Rarely, blood-count problems such as low platelets or agranulocytosis have been reported.
Cimetidine may also mask symptoms of a more serious stomach condition, so unexplained or persistent symptoms should be evaluated. This is general information, not medical advice. Give your prescriber and pharmacist a full list of your medicines and health conditions, and follow their guidance on dosing and monitoring.
This Cimetidine information was written and reviewed against authoritative U.S. medical sources — MedlinePlus (U.S. National Library of Medicine), DailyMed, and FDA prescribing information — and checked for accuracy. It is provided for education and is not a substitute for professional medical advice.
Verify the official label: Cimetidine on DailyMed (FDA)
Reviewed against FDA labeling · Last reviewed July 2026
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Medical disclaimer: This information is provided for general educational purposes only and is not medical advice. It is not a substitute for professional diagnosis or treatment. Always consult a licensed physician, pharmacist, or other qualified healthcare provider before starting, stopping, or changing any medication or treatment. 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 doctor or 911 immediately.