Find out more about antibiotics, how they can help with bacterial infections, and if they’re safe to take when you have asthma.

What are antibiotics?

Antibiotics are used to treat bacterial infections. For example, bacterial chest infections and some types of pneumonia.

They are not used for viral infections like colds and flu, or chest infections caused by viruses.

It can sometimes be difficult to tell the difference between infections caused by bacteria and those caused by viruses. This makes it tricky to know if antibiotics will help you or not. Your doctor may need to test a sample of your mucus to be sure and will look for signs like:

  • a high temperature that gets worse after a few days
  • your phlegm being green or brown 
  • not feeling better after three weeks
  • your asthma symptoms getting worse.

Antibiotic resistance

In the past, a lot of antibiotics were prescribed ‘just in case’. We now know this causes antibiotic resistance, which is when overuse of antibiotics means they stop being effective.

To avoid using antibiotics unnecessarily, your doctor might give you a ‘delayed prescription’ for antibiotics, which you can take only if you don’t start to feel better in a few days.

Never take antibiotics if you don’t need them. You should not take them for a viral infection. If you do need antibiotics to deal with a bacterial infection, take them exactly as directed by your GP. The NHS has more information about using antibiotics safely.

Can antibiotics help my asthma symptoms?

The best way to treat asthma is by taking a regular preventer medicine, usually as an inhaler, and a reliever inhaler when needed. Asthma cannot be treated with antibiotics because the inflammation in your airways isn’t caused by bacteria.

But your GP may prescribe antibiotics if a bacterial infection, such as a bacterial chest infection, is making your asthma symptoms worse.

You may be given antibiotics to deal with the infection and may need oral steroids to deal with the asthma symptoms.

Your asthma symptoms should get better, but this is because the antibiotics are treating the underlying cause of your asthma symptoms, not the asthma symptoms themselves.

Not all chest infections are caused by bacterial infection. If you have a chest infection caused by a viral infection, antibiotics will not help. Read more about chest infections.

See your GP or asthma nurse urgently if:

your asthma symptoms are getting worse. Even if you don't need antibiotics, you still need support to get your symptoms back on track.

'Rescue packs'

Very occasionally GP’s may prescribe antibiotics in advance as part of a ‘rescue pack’ for people with asthma. Antibiotics prescribed in this way should always come with a detailed emergency action plan, explaining what medicines should be started and when.

Even if you do have a ‘rescue pack’ including antibiotics at home, let your GP know if you need to start your treatment, or if your symptoms are getting worse.

Antibiotics for severe asthma

There are some types of severe asthma that may be treated with on-going antibiotics as an add-on treatment prescribed by a hospital specialist. Find out more about treatments for severe asthma.

Do I need antibiotics for an asthma attack?

Antibiotics cannot help with asthma attacks and guidelines do not recommend routinely prescribing antibiotics after an asthma attack.

You should only be prescribed antibiotics after an asthma attack if there is strong evidence that you have a bacterial infection. For example, a bacterial chest infection or pneumonia.

Find out what to do in an asthma attack.

Is it safe to take antibiotics when you have asthma?

There are lots of different types of antibiotics. Your GP will prescribe the one that’s most effective against the infection you’ve got.

Most are safe to take if you have asthma and won’t make your asthma worse.

Some people get side effects with antibiotics, such as feeling sick or diarrhoea.

Talk to your GP if side effects are a problem, so they can see if there is a different type of antibiotic you could use.

It’s also worth checking with your GP or pharmacist if any antibiotics you’ve been prescribed are safe to take alongside your asthma medicines and any other medicines you’re taking. For example, antihistamines for hay fever.

Allergic reactions to antibiotics

Some people (around 1 in 15) have an allergic reaction to antibiotics, particularly to penicillin. Mostly this is a mild allergic reaction and can be treated.

More rarely people have a severe allergic reaction (anaphylaxis). The risk of a severe allergic reaction is higher if you have a history of asthma, eczema, or hay fever.

A severe allergic reaction may mimic asthma symptoms – coughing, wheezing, and shortness of breath. Always call 999 if you have a severe allergic reaction.

Get support

Call our Helpline for support with your condition. Get advice on your medicines, symptoms or travelling with a lung condition, or just call us to say hello.

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