Prescription vs.OTC: Prescription by Doctor required

Stomach and intestine ulcers can be effectively treated with Cimetidine. The medication also helps prevent the recurrance of ulcers, throat and stomach problems that occur because of excess acid present in the stomach. GERD can also be treated with Cimetidine. The drug reduces the extra acid present in the stomach, thus reducing symptoms like stomach pain, heart burn, constant cough, and sleep problems. The drug also protects or digestive tract from serious damage because of the acid present.

Cimetidine is a part of a group of drugs known as H2 blockers. The drug is also available over the counter as it is commonly taken by individuals who suffer from heartburn.

You can take the drug orally, as per the directions of your doctor or pharmacist. The dosage of the drug and the time period for which it should be taken generally depends on the severity of your condition and your body’s response to it.

Side effects commonly occur in case of most medicines. Most patients experience very minor side effects which go away with time. Only a few suffer from a severe allergic reaction or any major problems. Symptoms of an allergic reaction may include rashes, itching, problems with breathing and swelling of the face, throat and tongue. Some of the common side effects that you may experience are headache, diarrhea, and dizziness. Some serious side effects that you may experience are hallucinations, depression, confusion, problems with urinations etc. It is best that you consult your doctor if you experience any major side effects.

The drug should not be taken for more than a fortnight without consulting your doctor first. Moreover, ensure that you take only 2 doses in a span of 24 hours.

Information given here is based on the salt content of the medicine. Uses and effects of the medicine may vary from person to person. It is advisable to consult a Gastroenterologist before using this medicine.
  • Duodenal Ulcer

    Cimetidine is used in the treatment of ulcers in the small intestine.
  • Gastric Ulcer

    Cimetidine is used in the treatment of ulcers in the stomach.
  • Gastroesophageal Reflux Disease

    Cimetidine is used for the treatment of a condition where the acid produced in the stomach causes irritation in the food pipe.
  • Zollinger-Ellison Syndrome

    Cimetidine is used to relieve the symptoms of this rare condition where the acid secretion in the stomach is abnormally high.
  • Allergy

    Not recommended in patients with known allergy to Cimetidine or other H2 antagonists.
  • How long is the duration of effect?

    The effect of this medicine lasts for an average duration of 4 to 5 hours after an intravenous dose and 4 to 8 hours after an oral dose.
  • What is the onset of action?

    The effect of this medicine can be observed in less than 1 hour after an oral dose and less than 30 minutes after an intravenous dose.
  • Are there any pregnancy warnings?

    This medicine is recommended in pregnant women only if benefits overweigh the risks.
  • Is it habit forming?

    No habit forming tendencies were reported.
  • Are there any breast-feeding warnings?

    This medicine is known to excreted through the breastmilk. It is not recommended for breastfeeding women.
  • Missed Dose instructions

    Take the missed dose as soon as you remember. If it is almost time for the next scheduled dose, then the missed dose can be skipped.
  • Overdose instructions

    Seek emergency medical treatment or contact the doctor in case of an overdose.
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This medication works as a histamine H2-receptor antagonist by binding to and inhibiting histamine receptors. This blocks histamine’s ability to induce suppressor T lymphocyte activities and to block natural killer cell activity and interleukin-2 production.

Whenever you take more than one medicine, or mix it with certain foods or beverages, you"re at risk of a drug interaction.

  • Interaction with Alcohol


    Consumption of alcohol is not recommended in patients receiving Cimetidine. Any symptoms of adverse effects like dizziness, breathing difficulty should be reported to the doctor. Performing activities that require mental alertness like driving, operating machinery should be avoided.
  • Interaction with Lab Test


    Information not available.
  • Interaction with Medicine


    Cimetidine may increase the effect of antidiabetics medicines like glipizide, glimepiride which may lower the blood glucose levels. Monitoring of blood glucose levels is necessary. Any symptoms like dizziness, tiredness, weakness should be reported to the doctor. Dose adjustments or an alternate medicine should be considered based on the clinical condition.


    Cimetidine may increase the concentration of loperamide and may cause dizziness, lightheadedness, irregular heart rhythm, and difficulty of breathing. Inform the doctor if you are receiving either of the medications. Dose adjustments or an alternate class of medicine should be considered based on the clinical condition.


    Cimetidine may increase the concentration of phenytoin and may cause twitching eye movements, slurred speech, tremor, fainting, and breathing difficulty. Inform the doctor if you are receiving either of the medications. An alternate class of medicine should be considered based on the clinical condition.

    Antifungal agents

    Cimetidine will decrease the effect of antifungals, therefore inform the doctor if you are receiving any antifungals or gastric medications. Immediate medical treatment should be initiated if any symptoms of an increase in the severity of fungal infection appear. An alternate medicine should be considered based on the clinical condition.
  • Interaction with Disease

    Gastrointestinal Bleeding

    Use of Cimetidine is not recommended for use if any symptoms indicating gastrointestinal bleeding exists. Consult your doctor if there is blood in vomit or the stools are bloody or black.
  • Interaction with Food


    Information not available.
Disclaimer: The information produced here is best of our knowledge and experience and we have tried our best to make it as accurate and up-to-date as possible, but we would like to request that it should not be treated as a substitute for professional advice, diagnosis or treatment.

Lybrate is a medium to provide our audience with the common information on medicines and does not guarantee its accuracy or exhaustiveness. Even if there is no mention of a warning for any drug or combination, it never means that we are claiming that the drug or combination is safe for consumption without any proper consultation with an expert.

Lybrate does not take responsibility for any aspect of medicines or treatments. If you have any doubts about your medication, we strongly recommend you to see a doctor immediately.

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Content Details
Written By
PhD (Pharmacology) Pursuing, M.Pharma (Pharmacology), B.Pharma - Certificate in Nutrition and Child Care
Reviewed By
MBBS, Master in Healthcare Administration, Diploma in Occupational Health
General Physician
Table of Content
About Cimetidine
What are the uses of Cimetidine
What are the contraindications of Cimetidine ?
What are the side effects of Cimetidine ?
Key highlights of Cimetidine
What are the dosage instructions?
Where is the Cimetidine approved?
How does this medication work?
What are the interactions of Cimetidine ?