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Cimetidine oral

Updated 2 Feb 2023 | H2 receptor antagonists


Oral formulations of cimetidine.

Drugs List

  • cimetidine 200mg tablets
  • cimetidine 200mg/5ml oral solution
  • cimetidine 200mg/5ml oral solution sugar-free
  • cimetidine 400mg tablets
  • TAGAMET 200mg/5ml syrup
  • Therapeutic Indications


    Acid aspiration during labour: prophylaxis
    Before general anaesthesia in patients at risk of acid aspiration
    Dyspepsia associated with hyperacidity
    Gastro-oesophageal reflux disease
    Prevention of duodenal or benign gastric ulcer recurrence
    Prophylaxis of stress induced GI haemorrhage in the seriously ill
    Reduction of fluid loss and malabsorption due to short bowel syndrome
    Reduction of gastric acid secretion prior to taking pancreatin
    Stomal ulcer
    Treatment of benign gastric or duodenal ulcer - NSAID associated
    Treatment of duodenal and benign gastric ulcers
    Zollinger-Ellison syndrome (and other hypersecretory conditions)



    400mg twice daily (400mg with breakfast and 400mg at bedtime) for at least four weeks.
    Total daily dose should not exceed 2.4g.

    Duodenal or benign gastric ulcer
    800mg once daily at bedtime. Or 200mg three times daily (with meals) followed by 400mg at bedtime. Total daily dose of 1g.
    If inadequate, increase the dose to 400mg four times daily. Total daily dose of 1.6g. Treatment should be administered for at least four weeks.
    Treatment in benign gastric ulcer should be at least six weeks. Treatment in ulcer associated with non-steroidal anti-inflammatory agents should be administered for at least eight weeks. A further course of treatment may be required, particularly in patients who may benefit from a reduction of gastric secretion.
    For patients who have responded to treatment dose may be reduced to 400mg in the morning and 400mg at bedtime or a single dose of 400mg at bedtime. This dose may also be administered to prevent relapse, particularly in patients with benign peptic ulcer disease who have responded to the first course of treatment.

    Oesophageal reflux disease
    400mg four times daily (with meals and at bedtime) for 4 to 8 weeks. Total daily dose of 1.6g.

    Zollinger-Ellison syndrome and other hypersecretory conditions
    400mg four times daily, dosage may be increased if necessary.

    Prophylaxis of stress induced gastrointestinal haemorrhage in the seriously ill
    200mg to 400mg every 4 to 6 hours.

    Prophylaxis of acid aspiration syndrome
    400mg 90 to 120 minutes before the induction of anaesthesia, or in obstetrics at the start of labour. A dose of up to 400mg may be repeated every 4 hours, as required. Total daily dose of 2.4g.

    Reduction of gastric acid prior to taking pancreatic enzyme supplements
    800mg to 1600mg daily 60 to 90 minutes before meals in four divided doses, according to response.


    Children aged 1 to 18 years
    25mg/kg to 30mg/kg of body weight daily, in divided doses.

    Children under 1 year
    20mg/kg body weight daily, in divided doses.

    Patients with Renal Impairment

    The following dosages are suggested:

    Creatinine clearance 0 to 15ml/minute: 200mg twice daily.
    Creatinine clearance 15 to 30ml/minute: 200mg three times daily.
    Creatinine clearance 30 to 50ml/minute: 200mg four times daily.
    Creatinine clearance more than 50 ml/minute: Normal dosage.

    Cimetidine is removable by haemodialysis but not to any significant extent by peritoneal dialysis.


    None known

    Precautions and Warnings

    Children under 1 year
    Glucose-galactose malabsorption syndrome
    Hereditary fructose intolerance
    History of peptic ulcer
    Lactose intolerance
    Renal impairment

    Reduce dose in patients with renal impairment
    Exclude gastric cancer before commencing treatment
    Oral solution with maltitol unsuitable in hereditary fructose intolerance
    Some brands contain Sunset Yellow (E110) - can trigger allergic reactions
    Some formulations contain hydroxybenzoate
    Some formulations contain lactose
    Some formulations contain propylene glycol
    Monitor patients on prolonged therapy
    Monitor patients with a history of peptic ulcer on concomitant NSAIDs
    Advise patients to report new or recently changed dyspeptic symptoms

    It is recommended to closely monitor prothrombin time when cimetidine is used concurrently.

    Pregnancy and Lactation


    Use cimetidine with caution in pregnancy.

    Animal studies have shown cimetidine does cross the placenta. Schaefer (2015) states cimetidine may be safe to use during pregnancy as it is considered well tolerated by both mother and foetus. Briggs (2015) states there is no increased risk of the foetus developing congenital abnormalities, however the manufacturer suggests to only administer cimetidine during pregnancy if the clearly considered necessary.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use cimetidine with caution in breastfeeding.

    Animal studies have shown cimetidine is excreted in breast milk. High concentrations may accumulate in infants if cimetidine is administered during breast feeding, however the clinical significance is unknown (Briggs et al, 2015). Hale (2014) states short term use of cimetidine is compatible to be administered during breastfeeding. There are other preferred drugs of choice to administer during breastfeeding if necessary (Schaefer et al, 2015). The manufacturer suggests to not administer cimetidine during breastfeeding unless clearly considered necessary.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Acute pancreatitis
    Altered liver function tests
    Aplastic anaemia
    Blood disorders
    Heart block
    Interstitial nephritis
    Reversible confusional states
    Reversible liver damage
    Serum creatinine increased
    Sinus bradycardia


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: June 2017

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

    Summary of Product Characteristics: Cimetidine 200mg Tablets BP. Accord Healthcare Limited. Revised May 2016.

    Summary of Product Characteristics: Cimetidine 400mg Tablets BP. Accord Healthcare Limited. Revised May 2016.

    Summary of Product Characteristics: Cimetidine 800mg Tablets BP. Accord Healthcare Limited. Revised May 2016.

    Summary of Product Characteristics: Cimetidine 200mg/5ml oral solution. Rosemont Pharmaceuticals Ltd. Revised May 2013.

    Summary of Product Characteristics: Tagamet 400 mg tablets. Chemidex Pharma Ltd. Revised May 2016.

    Summary of Product Characteristics: Tagamet 800 mg tablets. Chemidex Pharma Ltd. Revised May 2016.

    The Renal Drug Handbook. 3rd edition. (2009) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    NICE Evidence Services Available at: Last accessed: 28 June 2017

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