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Not sure why you’ve been prescribed antibiotics, or if you should be taking them for your asthma?

Antibiotics are a group of drugs used to treat a variety of bacterial infections such as pneumonia or urinary tract infections in people with and without asthma.

Are antibiotics used to treat asthma?

The inflammation that’s associated with asthma isn’t caused by bacteria, so antibiotics won’t help. It needs to be kept under control with your preventer inhaler and/or oral steroids.

The current guidelines for healthcare professionals on how to treat asthma don’t recommend automatically prescribing antibiotics after an asthma attack. But studies show that more than half of people who have asthma attacks are prescribed antibiotics anyway – either because it’s hard to tell the difference between a bacterial infection and asthma-related inflammation, or because patients have asked for antibiotics.

Some early research suggests that a group of antibiotics called macrolides (which include medicines called clarithromycin and erythromycin) might be used to treat asthma in the future. They’re currently used to treat a range of bacterial infections, but more research is needed before they can be recommended for asthma.

How infections affect asthma

Having a cold or flu can leave anyone feeling run down and fed up, but people with asthma tell us that coughs and colds often make their asthma symptoms worse or even trigger asthma attacks. If you find this happens, it might be because mucus from your runny nose is dripping down the back of your throat, or because the tissues in your airways are already inflamed by infection – or even that you’re having to breathe dry, cold air through your mouth because your nose is blocked.

Bacteria or virus?

Not all infections are caused by bacteria. Most chest infections, coughs and colds are caused by viruses. A virus is a completely different type of microbe that isn’t treatable with antibiotics.

It can be difficult, even for doctors, to tell the difference between bacterial and viral infection, so in the past a lot of antibiotics were prescribed ‘just in case’. We now know that this causes a problem called ‘antibiotic resistance’ where the more bacteria are exposed to antibiotics, the more likely it is they will adapt and learn how to survive them. That means there are fewer effective treatments for people who really need them – babies, older people or those having major surgery.

These days, doctors are much less likely to prescribe antibiotics ‘just in case’. They will only prescribe them if you really need it.

How to treat a virus

Viral infections are usually self-limiting – that is, if you look after yourself, your body will get rid of the infection itself within two weeks. If you thought antibiotics helped you recover from a virus in the past, it was actually just that the virus had come to its natural end.

Read our advice on reducing the risk of infection and looking after your asthma when you have a cold or flu.

Speak to your GP or asthma nurse if:

  • your high temperature gets noticeably worse after a few days
  • you notice a change in the colour of your phlegm from clear to yellow or green
  • you are not feeling better after three weeks
  • you are struggling to control your asthma during a cold or infection.

These are all signs that you may have developed a bacterial infection. Your healthcare professional may prescribe antibiotics, or ‘step up’ your medicine to help control your asthma while your body fights off the infection.

To reduce the number of antibiotics being taken by people who don’t need them, your GP may decide on delayed prescribing – they’ll give you a prescription for antibiotics which you can collect if you don’t start to feel better within a few days.

How can I get the best from a course of antibiotics?

If you are prescribed antibiotics for any reason, remember to finish the whole course. It’s tempting to stop taking them when you start to feel better, but that can give the bacteria a chance to recover and make you feel worse again. It’ll also make the antibiotic less effective next time you need them.

If you finish a course of antibiotics for a chest infection and continue to have asthma symptoms, go back to your GP – as you may need to be treated with steroid tablets.

Possible side effects of antibiotics

Nine in ten people will take antibiotics without any side effects. When they do happen, side effects of antibiotics usually affect the digestive system, and can include:

  • nausea
  • vomiting
  • diarrhoea
  • bloating or stomach pain.

More rarely, they can trigger an allergic reaction, such as an itchy skin rash. Confusingly, an allergic reaction can also show up as asthma-like symptoms: coughing, wheezing, or a tight throat. Mild allergies can usually be treated with antihistamines, but you should contact your GP if they don’t improve.

A very few people are severely allergic to antibiotics, and develop anaphylaxis, which can be life-threatening. The initial mild allergic symptoms can then lead to:

  • rapid heartbeat and increasing difficulty breathing
  • feelings of fear
  • light-headedness and confusion
  • unconsciousness.

If you think you have anaphylaxis, call 999 for an ambulance immediately. If you are allergic to penicillin, you will also react to other related antibiotics such as amoxicillin or flucloxacillin, and your healthcare professional will need to prescribe other antibiotics to treat you safely. Make sure any drug allergy is added to your medical record and to any medical card or bracelet you carry so you can be treated safely in the future.

Antibiotics and pregnancy

Whether you have asthma or not, there are a few restrictions on the use of antibiotics when you’re pregnant. In general, and if you are not allergic to them, penicillins are considered to be safe. Read the NHS’s advice about antibiotics and pregnancy and speak to your healthcare professional if you have any questions.

Can antibiotics cause asthma?

One study has suggested that children given antibiotics as a child (or whose mothers took antibiotics while pregnant) are more likely to develop asthma. But it also found that their brothers and sisters who were not exposed to antibiotics also went on to develop asthma, which suggests that antibiotics aren’t the direct cause. We know that asthma can run in families, so it may just be that children who are more likely to develop asthma are also more likely to have had bacterial infections which were treated with antibiotics.

The link could also happen because it can take several years to diagnose asthma in children. In the meantime, their asthma symptoms may be mistakenly treated with antibiotics – which didn’t cause the asthma but didn’t relieve symptoms either. More research is needed to work out if there is a link.

Who can I speak to?

If you’re concerned 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. Whether you want to check something your GP has told you, or are confused about how your medicines work, they’re here to help.

Last updated September 2016

Next review due September 2019