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Wondering whether it’s safe to take antibiotics when you have asthma? Or whether you need antibiotics for a chest infection? We give you the facts about asthma and antibiotics.

Antibiotics, like flucloxacillin and doxycycline, are a group of drugs used to treat bacterial infections - for example, some types of pneumonia and bacterial chest infections.

Will antibiotics make my asthma symptoms better?

Unfortunately, antibiotics won’t help.

When your asthma plays up, your airways get inflamed, making you cough, wheeze and struggle to breathe. But because the inflammation isn’t caused by bacteria, it can’t be treated with antibiotics. Taking your regular asthma medicine is the best way to help ease your asthma symptoms.

To confuse things, if your doctor thinks your asthma symptoms are worse because of a bacterial chest infection, they might give you antibiotics. You’re likely to be prescribed steroids at the same time to treat any asthma inflammation. If this combination works, you’ll feel better. It might seem like the antibiotics have ‘cured’ your asthma – but they haven’t, they’ve sorted the chest infection.

Do I need antibiotics after an asthma attack?

Guidelines don’t recommend prescribing antibiotics after an asthma attack.

However, studies show that more than half of people who have asthma attacks are given antibiotics anyway. This might be because infections can trigger an asthma attack, so people are often given antibiotics to treat the underlying cause. Again, it’s confusing.

Is this a chest infection or asthma?

Annoyingly, it can be both.

Read about how chest infections, colds and the flu can trigger your asthma symptoms.

Looking after your asthma when you have an infection

If your asthma symptoms are still difficult to control even though you’re taking your normal asthma medicines, try speaking to your doctor about increasing your asthma medicine while you recover. Read more on looking after your asthma when you have a chest infection.

Is it safe to take antibiotics when you have asthma?


But a few people react badly to antibiotics. A severe allergic reaction may mimic asthma symptoms – coughing, wheezing and shortness of breath. You should call 999 if you experience this.

Tips to help your antibiotics work properly

Bacteria are always trying to adapt so antibiotics can’t kill them. This is called ‘antibiotic resistance’. By taking antibiotics as prescribed, you can help avoid this.

Make sure you:

  • Take the course right to the end, even after you’re better
  • Try taking both your antibiotics and asthma medicine together every day, to help you remember
  • Don’t keep antibiotics ‘for next time’ – take any unused antibiotics to your pharmacy who can throw them away safely
  • Don’t share antibiotics with others

My doctor won’t give me antibiotics, even though I’m very unwell

Most chest infections, coughs and colds are caused by viruses, and viruses can’t be treated with antibiotics.

It can be difficult, even for doctors, to tell the difference. So, in the past, a lot of antibiotics were prescribed ‘just in case’. We now know this causes antibiotic resistance.

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

Signs you might need antibiotics

  • your high temperature gets worse after a few days
  • your phlegm changes colour from clear to yellow or green 
  • you’re not feeling better after three weeks
  • you’re struggling to control your asthma.

Talking to your doctor about antibiotics

If you think you shouldn’t have been prescribed antibiotics, or you don’t think they’re making a difference, try asking your doctor these questions:

  •  “Is it definitely a bacterial infection?”
  • “How soon will I know if these antibiotics are working?”
  • “Is there anything else I can do to treat my infection and asthma symptoms?”

I’ve finished my antibiotics, but my asthma symptoms are still bad  

If you finish a course of antibiotics and continue to have asthma symptoms, go back to your GP.  

Can antibiotics cause asthma in adults or children?

People with asthma are often prescribed antibiotics for two reasons:

  1. Asthma can make you prone to chest infections
  2. Chest infections can be a trigger for asthma

Because of this, there’s lots of conflicting information about asthma and antibiotics. Some studies suggest antibiotics might cause asthma, others say they might cure it or help you get better more quickly after an asthma attack. Much more research is needed.

Who can I speak to?

If you’re worried about your medicines, speak to your GP or asthma nurse.

You can also call our Helpline on 0300 222 5800 and talk to an expert asthma nurse between 9am and 5pm, Monday to Friday. 

Last updated February 2018

Next review due September 2019