Cimetidine Tablets and Tagamet® for Heartburn, GERD, and Ulcers

What Cimetidine Is and How It Works

Cimetidine is an H2 receptor blocker used to reduce stomach acid. It helps relieve and prevent heartburn, treats gastroesophageal reflux disease (GERD), and helps heal gastric and duodenal ulcers. It is available in tablets, including cimetidine over the counter 200 mg strengths for heartburn, and higher strengths by prescription for ulcer therapy and GERD. Typical dosing is once or twice daily, and timing can be with or without food.

YouDrugstore.com is a licensed Canadian pharmacy based in Manitoba that follows Canadian pharmacy standards. Our pharmacists review prescriptions before dispensing, and you can order online with friendly customer-service chat during posted hours for support. We offer brand and generic medicines at Canadian prices, and also carry OTC health products.

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Dosage and Usage

• Heartburn prevention and relief (OTC): 200 mg by mouth once or twice daily. For prevention, take 200 mg 30–60 minutes before food or drink that triggers heartburn. Do not exceed 400 mg per day without medical advice.
• GERD and ulcer treatment (Rx): Common regimens include 400 mg twice daily or 800 mg at bedtime. Some regimens use 300 mg four times daily for active ulcers. Maintenance therapy may be 400 mg at bedtime. Follow the prescribed plan.
• Swallow tablets with water. With or without food is acceptable. Avoid high-fat, late meals if they worsen symptoms.
• Missed dose: Take it when remembered unless it is near the next dose. Do not double doses.
• Kidney impairment: Dose adjustments may be required. Prescribers usually reduce dose or extend intervals.
• Storage: Store your tablets at 15–30°C (59–86°F). Keep them dry and away from heat and moisture. Keep out of reach of children.
• Travel: Carry your medication in original packaging. Pack extra tablets, and keep them in your hand luggage. Avoid leaving medicine in a hot car.

Benefits and Savings

Cimetidine reduces acid quickly and helps relieve heartburn, sour stomach, and acid indigestion. It can lower nighttime acid and reduce ulcer pain while healing occurs. The tablet format is convenient and can be taken flexibly with meals. OTC options support short-term management, while prescription strengths address sustained GERD or ulcer therapy.

Buying from a Canadian pharmacy often lowers costs. Typical savings are 60–80% compared to usual U.S. prices, especially for longer courses or higher strengths. You can choose generic cimetidine or the brand Tagamet® where available. Multi-month supplies can further reduce the per-month cost.

Side Effects and Safety

• Common: Headache, dizziness, diarrhea, constipation, fatigue.
• Less common: Nausea, abdominal discomfort, rash, muscle aches.
• CNS effects (more likely in older adults or with high doses): Confusion, agitation, depression, hallucinations.
• Hormonal effects (with higher doses or long-term use): Gynecomastia, decreased libido, erectile dysfunction, menstrual changes.
• Serious but rare: Hepatitis, pancreatitis, liver enzyme elevations, agranulocytosis, aplastic anemia, thrombocytopenia, severe allergic reactions.
• Interactions: Cimetidine inhibits several CYP450 enzymes. Levels of warfarin, theophylline, phenytoin, diazepam, tricyclic antidepressants, lidocaine, metoprolol, and others may increase. It is contraindicated with dofetilide. Acid reduction may lower absorption of ketoconazole, atazanavir, iron salts, and erlotinib.

People with severe kidney impairment, significant liver disease, or a history of severe reactions to H2 blockers need careful assessment. Alarm symptoms such as trouble swallowing, vomiting blood, black stools, unexplained weight loss, or persistent chest pain require prompt medical evaluation.

Onset Time

Relief usually begins within 30–60 minutes after a dose. Effects on acid secretion last about 4–6 hours for 200 mg, and longer with higher or repeated doses. For ulcers or chronic GERD, symptom improvement may appear within days, while healing can require 4–8 weeks depending on the regimen and condition.

Compare With Alternatives

Other H2 blockers include famotidine, which has fewer drug interactions and may be preferred for some patients. Proton pump inhibitors (PPIs) offer stronger and longer acid suppression for frequent or severe symptoms or confirmed esophagitis.

Rabeprazole is a once-daily PPI used for GERD and ulcer healing. The brand Pariet® and generic rabeprazole have a higher potency of acid suppression than H2 blockers. For patients who need flexible dosing or dual delayed release, Dexilant® (dexlansoprazole) is another PPI option. PPIs may take 1–4 days to fully control symptoms but often provide more complete healing in erosive disease.

Antacids and alginates provide quick, short-lived relief and can be combined with cimetidine for breakthrough symptoms. Ranitidine is no longer available in many markets.

Combination Therapy

For occasional heartburn, cimetidine can be paired with an antacid for rapid relief and sustained control. For H. pylori ulcer therapy, protocols generally use a PPI plus antibiotics rather than cimetidine. Acid reduction can affect the absorption of certain antifungals and antivirals, so scheduling or alternative therapy may be needed. Cimetidine’s CYP450 inhibition raises levels of several drugs; clinicians adjust regimens accordingly.

Do not combine high-dose H2 blockers and PPIs without medical direction. Patients with frequent NSAID use may need gastroprotection. Long-term acid suppression can affect vitamin B12 and magnesium status; monitoring may be warranted in prolonged therapy.

Patient Suitability and Cost-Saving Tips

Cimetidine suits adults with episodic heartburn, mild GERD, or healing ulcers under a prescriber’s care. It may help those who need short-term nocturnal acid control. People with kidney impairment, multiple medications, older adults, or those with complex conditions need individualized assessment due to interaction and CNS risk. Persistent or severe symptoms, difficulty swallowing, gastrointestinal bleeding, or unintended weight loss require evaluation before continuing therapy.

To lower costs, consider generic tablets, larger pack sizes, and multi-month supplies when appropriate. You can set reorder reminders so you do not run out during treatment. For current offers and bulk options, see our cimetidine coupon page.

If you want to learn more about related conditions, explore Heartburn and Gastroesophageal Reflux Disease on our site. For broader GI symptom reading, you can review the article Trimebutine Uses Dosage And Side Effects Explained.

Authoritative Sources

See the Health Canada Drug Product Database entry for cimetidine tablets for Canadian product details: Health Canada Drug Product Database.

Review U.S. prescribing information and labels on DailyMed for cimetidine tablets: DailyMed Cimetidine Tablets.

You can order brand and generic acid reducers from YouDrugstore.com with secure checkout. Our pharmacy team verifies prescriptions, and your order ships with prompt, express, cold-chain shipping available for temperature‑sensitive items.

Information on this page is for general education. It does not replace advice from your own healthcare professional. Always follow your prescriber’s directions and the product label.