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Carbocisteine

Carbocisteine is used to thin and loosen mucus in the airways. Learn how to use the medication, its common side effects, special precautions to watch out for, and more.
  • Article last reviewed 11 November 2025
  • 6 mins read

What is this medication for?

This medication is also known as carbocysteine. It is a mucolytic that works by thinning and loosening mucus in the airways, helping to clear a chest congestion, thus making breathing easier. It may come in the form of a syrup, tablet or capsule. It may also be found in combination with other ingredients for the relief of runny nose and cough.   

How should I take or use this medication?

  • Take this medication as recommended by your healthcare professional. Consult your healthcare professional if you are not sure how to take this medication correctly.
  • This medication may be taken with or without food.
  • For syrups, shake the bottle well before use.
  • If your symptoms persist or worsen after one week of taking this medication, please talk to your healthcare professional. 

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

Carbocisteine may be taken when required for a short period of time. This means that you do not have to take the medication if you do not have any symptoms. If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue normally. Do not take two doses or 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:

  • You are allergic to carbocisteine, or any other ingredients used in this medication.
  • You are pregnant, planning to become pregnant or breastfeeding.
  • You are taking any other medications, including supplements, traditional medications and herbal remedies.
  • You have existing conditions such as gastric ulcers, liver or kidney problems and lung conditions e.g. Chronic Obstructive Lung Disease (COPD) or severe uncontrolled asthma.
  • You have a cough with thick yellow or green phlegm or mucus, or blood.
  • You have a fever of more than 38.6oC.
  • You lose weight even though you are not trying to do so.
  • You have night sweats.
  • Your cough lasts for more than 3-4 weeks.
  • You start having new symptoms during self-treatment. 

What are some common side effects of this medication? ​

  • Nausea
  • Vomiting
  • Stomach pain  
  • Diarrhoea

These side effects are usually mild and will pass quickly. If the side effects are bothersome, do not go away or get worse, speak to your healthcare professional. 

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 this medication and see your doctor immediately. 

You can also find out about drug allergies by watching these videos:
They are available in English, 中文, Melayu and தமிழ்: Drug Allergies

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

Let your healthcare professional know if you are taking, or planning to take any other herbal products, supplements or medications.  

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

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. The workgroup consists of cluster partners (NHG Health, 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.