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Cimetidine

Cimetidin Genericon, Ulcostad · ATC code A02BA01

Also known as: Cimetidin, Simetidin

Key facts
Active substance
Cimetidine
ATC code
A02BA01
Authorisation
authorised nationally; no central EU authorisation
Information as of
2026-10-29

Key facts

Cimetidine is an H2-receptor antagonist that inhibits gastric acid secretion. Per the US prescribing information, it is used for duodenal and gastric ulcers, erosive GERD and hypersecretory conditions.

What it is used for

  • Short-term treatment of active duodenal ulcer and maintenance therapy at reduced dose after healing
  • Short-term treatment of active benign gastric ulcer
  • Erosive gastroesophageal reflux disease (endoscopically diagnosed erosive esophagitis)
  • Pathological hypersecretory conditions (e.g. Zollinger-Ellison syndrome, systemic mastocytosis, multiple endocrine adenomas)

Dosing

  • Active duodenal ulcer: dose of choice 800 mg at bedtime; continue for 4 to 6 weeks unless healing is shown endoscopically
  • Duodenal ulcer maintenance: 400 mg at bedtime
  • Benign gastric ulcer: 800 mg at bedtime, or 300 mg 4 times a day with meals and at bedtime
  • Erosive GERD: 1,600 mg daily in divided doses (800 mg twice daily or 400 mg 4 times daily) for 12 weeks
  • Hypersecretory conditions: 300 mg 4 times a day, usually not exceeding 2,400 mg per day
  • Severe renal impairment: 300 mg every 12 hours; further reduction may be needed if liver impairment is also present
  • Do not take antacids simultaneously, as they may interfere with absorption

Contraindications

  • Known hypersensitivity to the product

Important warnings

  • Symptomatic response does not preclude gastric malignancy
  • Reversible confusional states, mainly in severely ill patients; advancing age (50 or more years) and renal or liver disease are risk factors
  • Cardiac arrhythmias and hypotension after rapid intravenous bolus of the injection (rare)

Side effects

  • Headache, dizziness and somnolence
  • Diarrhea in approximately 1 in 100 patients
  • Reversible confusion, agitation, psychosis, depression, anxiety, hallucinations, usually within 2 to 3 days of starting
  • Gynecomastia with treatment of 1 month or longer (about 4% in hypersecretory states, otherwise 0.3% to 1%)

Interactions

  • Reduces hepatic metabolism of warfarin, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline and metronidazole
  • Warfarin: close monitoring of prothrombin time; dose adjustment may be needed
  • Antacids: may interfere with cimetidine absorption

Pregnancy and breastfeeding

  • No adequate studies in pregnant women; use only if clearly needed

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

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For patients

Patient information (US)

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

Austria

  • Cimetidin GenericonGenericon Pharma Gesellschaft M.B.H. · 1 register entry
  • UlcostadStada Arzneimittel Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Germany

  • H2-BlockerRatiopharm Gmbh · 1 register entry

Source: EMA – Article 57 product data (EU/EEA), as of 2026-10-29

Turkey

  • NovametBİLİM İLAÇ SAN. VE TİC. A.Ş. · 3 register entries

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

Brand names in 8 more European countries
Cyprus
Tenomet, Ulcomet
France
Cimetidine Arrow
Greece
Tagamet
Ireland
Cimeldine Clonmel Healthcare
Luxembourg
H2blocker
Netherlands
Cimetidine Accord, Cimetidine Cf
Portugal
Cim.
Romania
Cimetidina Arena

EMA – Article 57 product data (EU/EEA), 2026-10-29

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

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Sources

  1. U.S. Food and Drug Administration. Cimetidine (Mylan Pharmaceuticals Inc.) – Prescribing Information, 2026-07-15. DailyMed (NLM), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=06c0a509-026f-44e0-9975-a94a8de51d43
  2. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  3. EMA – Article 57 product data (EU/EEA), 2026-10-29. https://www.ema.europa.eu/en/human-regulatory-overview/post-authorisation/data-medicines-iso-idmp-standards-post-authorisation/public-data-article-57-database
  4. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: U.S. Food and Drug Administration (FDA), prescribing information, via DailyMed (NLM); public domain. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.