Medication Information Leaflet

What is this medication for?

High thyroid levels, or hyperthyroidism, is a condition where the thyroid gland in the body makes and releases too much thyroid hormone. People who have high thyroid levels may experience fast heartbeats, weight loss, feeling warm all the time and becoming more irritable. Carbimazole works by reducing the amount of thyroid hormone made. 

How should I take or use this medication?

• Do not stop taking your medications without checking with your healthcare professionals.
• This medication can be taken with or without food.

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

• If you miss a dose of Carbimazole, take it as soon as you remember. However, if it is near your next dose, skip the missed dose and resume your usual dosing schedule.
• Do not double your dose to make up for the missed dose. 

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

• Inform your healthcare professional if you:
  • are allergic to this medication or any of the other ingredients in this medication
  • are pregnant, planning to become pregnant or breastfeeding
  • have liver problems 
  • have blood disorders 

What are some common side effects of this medication?

• ​Generally, this medication has been well tolerated. Side effects usually have been mild and may go away as the body adjusts to the medication. 
• Common side effects include:
  • stomach upset
  • nausea
  • hair thinning

If you have any concerns regarding the side effects of Carbimazole, discuss with your healthcare professional. Do not stop taking medication on your own.

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

In some cases, Carbimazole may affect your liver and blood counts. Symptoms include one or more of the following:

• yellowing of your skin or eye 
• dark-coloured urine
• loss of appetite
• right upper abdominal pain
• muscle pain
• unusual bruising or bleeding
• feeling unusually tired

Warning: Low White Blood Cell Levels 

Very rarely, this medication may cause the number of white blood cells in your body to be low. This increases your chance of getting an infection. Stop this medication and see a doctor immediately if you have any signs of an infection such as fever, chills, bad sore throat, pain when you pass urine or have mouth sores or wounds that do not heal. 

This side effect has a very low chance of occurring. Most patients take this medication with minimal problems. Check with your doctor or pharmacist if you have any concerns regarding your medications.

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

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

There are some medications that may affect the level of Carbimazole in your body. Please inform your doctor or pharmacist before taking any medications, vitamins, herbal products and other traditional medications. Examples include:

• warfarin (a medication used for thinning of your blood)
• theophylline (a medication to help with your breathing) 

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

Disclaimer

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. 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.

Last updated on Aug 2022