What it is used for

Thick, sticky mucus in long-term lung conditions such as COPD and bronchiectasis

Read our guides:

COPD

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Carbocisteine is not commonly used off-label.

How it works

Carbocisteine changes the structure of mucus, making it thinner and less sticky. This makes it easier to cough up and can reduce the number of flare-ups.

Side effects

Like all medicines, Carbocisteine can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

feeling sick
stomach discomfort
diarrhoea

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

vomiting blood, or black or bloody poo, which can be signs of bleeding in the stomach
a skin rash with blisters

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

It is not suitable if you have an active stomach ulcer.
It is not recommended in the first 3 months of pregnancy.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.