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Drug Class: Commonly Known As: Category:
Histamine H2 Antagonist Adult

Cimetidine - What is it for

​Cimetidine works by reducing the amount of acid produced in the stomach. It is used to treat various conditions of the gastrointestinal (stomach and intestines) tract including:

  • Gastro-oesophagel reflux disease (a condition where the acid from the stomach goes back up from the food tube and throat causing pain and a burning sensation known as heartburn)
  • Treating and preventing ulcers of the gastrointestinal tract

Cimetidine - Side Effects, Precautions, and Contraindications

What side effects can Cimetidine cause?

Side effects of cimetidine include stomach pain, constipation, nausea, headaches and rarely blurred vision.

  • Please consult your healthcare professionals if the symptoms do not go away or when any unexplained or any unusual symptoms occur

Signs that your conditions may require further medical attention include:

  • Shortness of breath, hoarseness, wheezing, teeth erosion and ear infection
  • Alarm features including pain on swallowing, swallowing difficulty, blood in the stools or vomit, chest pain, unintended weight loss and jaundice (yellowing of the skin and whites of the eyes)
  • Heartburn symptoms occuring for more than 3 times a week with serious impact on quality of life
  • Heartburn symptoms continuing for more than 2 weeks despite self-treatment
  • Heartburn symptoms continuing for over 3 months regardless of self-treatment
  • You are over 40 years old and experiencing heartburn symptoms for the first time

If you experience any of these symptoms mentioned above, you should stop your medication and see your healthcare professionals immediately

The symptoms of a drug allergy include one or more of the following:
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

Before taking Cimetidine , what precautions must I follow?

Inform your healthcare professional if: 

  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant or breastfeeding
  • You have history of liver and/or kidney disease
  • You have been diagnosed with a rare inherited disease known as porphyria. This condition affects the production of red blood cells
  • You are taking any other medications, including supplements, traditional medications and herbal remedies

What food or medicine must I avoid when I take Cimetidine ?

​This medication may decrease the absorption of several vitamins and minerals such as:

  • Vitamins B12
  • Magnesium
  • Iron

Speak with your healthcare professionals to determine if you need to supplement these vitamins and minerals.

This medication interacts with many types of long-term medications. This may result in more side effects from your long-term medication, or may make other medications less effective. Medications affected by cimetidine include but are not limited to:

  • High blood pressure medication e.g. nifedipine
  • Medications for your heart e.g. metoprolol, amiodarone, flecainide
  • Medications to treat fungal infections e.g. ketoconazole. itraconazole
  • Medication to thin the blood e.g. warfarin
  • Medications to stabilise mood e.g. amitriptyline, diazepam
  • Medications to treat seizures e.g. carbamazepine, phenytoin
  • Medications to suppress the immune system e.g. tacrolimus, cyclosporine, hydroxychloroquine
  • Medications for migraine e.g. cafergot

Inform your healthcare professionals if you are taking or intend to take any other medications, supplements, traditional medications or herbal remedies.

Cimetidine - Dosage and How to Use

How should Cimetidine be used?

  • Do not stop taking your medication without checking with your healthcare professional
  • You may take this medication with or without food

What should I do if I miss a dose?

​If you forgot to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What should I do if I overdose?

Cimetidine - Handling

How should I handle Cimetidine safely?

Cimetidine - Storage

How should I store Cimetidine ?

;#Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#

How should I dispose of Cimetidine safely?

​Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin

Cimetidine - Additional Information

  • Updated on 12/17/2020 12:00:00 AM
  • Article contributed by PSS National Medication Information Workgroup PSS National Medication Information Workgroup
The information provided is not intended as medical advice. Terms of use. Information provided by SingHealth

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