Medication Information Leaflet

What is this medication for?

Metformin controls diabetes by helping your body to use insulin better. It also decreases the amount of sugar made by your liver, therefore reducing your sugar levels in the blood. It works together with lifestyle changes, such as having a healthy diet and regular exercise,  to reduce blood sugar levels.

How should I take or use this medication?

You can take this medication with or after food. This lowers your chances of getting stomach discomfort, nausea or diarrhoea.

What should I do if I forget to take or use this medication?

If you missed a dose, take the missed dose as soon as you remember. Remember to take it with food. If it is almost time for your next dose, take only the usual dose. 

Do not double your dose or use extra medication to make up for the missed dose.

What precautions should I take when taking or using this medication?

Inform your healthcare professional if 

• Are allergic to this medication or any of the other ingredients of this medication
• Are pregnant, planning to become pregnant, or breastfeeding
• Have a heart condition, kidney or liver problems
• Drink alcohol often
• Are going for a scan/ X-ray. You may need to stop taking metformin for a couple of days
• Are going for a surgery
• Suffered from diabetic ketoacidosis in the past. This is a complication of diabetes that is caused by an increase in the amount of ketones in your blood or urine, which causes your blood to become more acidic.

If you need to do fasting blood tests, do not take your medication until your blood has been taken and you have eaten.

What are some common side effects of this medication?

Like all medications, this medication may cause some possible side effects but not everyone experiences them. Consult your healthcare professional if any of the side effects becomes severe and bothersome.

The common side effects of Metformin include:

• Diarrhoea
• Nausea, vomiting, stomach discomfort
  • Take the medication with or after food to reduce nausea and vomiting
  • Avoid food that is too rich, spicy or has strong smells

What are some rare but serious side-effects that I need to seek medical advice 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

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

If the following serious side effects happen, you should consult your healthcare professional immediately:

• Lactic acidosis (a condition in which there is a build-up of lactic acid in th body, causing your blood to be more acidic) is a very rare but serious medical problem. The chances of this happening increase if your kidneys are not working properly. Symptoms of lactic acidosis include: 
  • Decreased appetite
  • Vomiting and stomach pains that continue for some time
  • A general feeling of being unwell accompanied with feeling cold or excessive tiredness
  • Fast, shallow breathing

What food or medication should I avoid when I take or use this medication?

Avoid taking alcohol with this medication as it increases the risk of lactic acid building up in your body.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How do I throw away this medication safely?

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

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Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup, and supported by the Ministry of Health. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Please visit www.moh.gov.sg/knowyourmeds and www.ndf.gov.sg for more information on medication.

Last updated on May 2023