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Largest trial of antibiotic amoxicillin for treating chest infections in children finds little effect

Press release issued: 28 September 2021

The largest randomised placebo-controlled trial of the antibiotic amoxicillin for treating chest infections in children - one of the most common acute illnesses treated in primary care in developed countries, has found it is little more effective at relieving symptoms than the use of no medication. The study, published in The Lancet and funded by the National Institute for Health Research (NIHR), was led by researchers from the University of Southampton and supported by centres at the Universities of Bristol, Oxford and Cardiff.

Although viruses are believed to cause many of these infections in children, whether or not antibiotics are beneficial in treatment of chest infections in children is still debated. While research so far in adults has shown that antibiotics are not effective for uncomplicated chest infections until now, there has not been the same level of research in children.

Researchers sought to test whether amoxicillin reduces the duration of moderately bad symptoms in children presenting with uncomplicated (non-pneumonic) lower respiratory tract chest infections in primary care. The trial recruited 432 children aged six months to twelve years-old with acute uncomplicated chest infections from primary care practices in England and Wales who were then randomly assigned to receive either amoxicillin or a placebo three times a day for seven days. Doctors or nurse-prescribers assessed symptoms at the start of the study and parents, with help from their children where possible, completed a daily symptom diary.

Only a small, non-significant, difference in the duration of symptoms were reported between the two groups: children given the placebo had symptoms which were rated moderately bad or worse for around 6 days on average after seeing the doctor, and those given antibiotics got better only 13 per cent quicker.

Furthermore, this was true even for the groups of children where the doctor heard sounds in the chest, the child had a fever, where the doctor rated the child as more unwell, the child coughed up phlegm or had a rattly chest, or the child was short of breath.

Just four children in the placebo group and five in the antibiotic group required further assessment at hospital. The costs to parents, such as the time needed to be off work or the cost of over-the-counter remedies, was very similar in both groups.

Paul Little, Professor of Primary Care Research at the University of Southampton and the study’s lead author, said: “Children given amoxycillin for chest infections where the doctor does not think the child has pneumonia do not recover much more quickly.

“Indeed, using amoxicillin to treat chest infections in children not suspected of having pneumonia is not likely to help and could be harmful. Overuse of antibiotics, which is dominated by prescribing of antibiotics in primary care, particularly when they are ineffective, can lead to side effects and the development of antibiotic resistance. Antibiotic resistance is one of the biggest threats to the health of the public, and in future could make much of what is currently routine medical practice very difficult or impossible - such having surgical operations or supporting people who are being treated for cancer.”

Alastair Hay, a GP and Professor of Primary Care at the University of Bristol’s Centre for Academic Primary Care, and one of the study’s co-authors, added: “The ARTIC PC trial is one of the very few studies to report on the effectiveness of prescribing antibiotics among younger children presenting with chest infections in primary care. It was designed to be able to detect a clinically important 3-day improvement in symptom duration.

“Our results suggest that unless pneumonia is suspected, clinicians should provide ‘safety-netting’ advice such as explaining what illness course to expect and when it would be necessary to re-attend but not prescribe antibiotics for most children presenting with chest infections.”


Antibiotics for lower respiratory tract infection in children presenting in primary care in England (ARTIC PC): a double-blind, randomised, placebo-controlled trial’ by P Little et al in The Lancet [open access]

Further information

About the Centre for Academic Primary Care

The Centre for Academic Primary Care (CAPC) at the University of Bristol is a leading centre for primary care research in the UK, one of nine forming the NIHR School for Primary Care Research. It sits within Bristol Medical School, an internationally recognised centre of excellence for population health research and teaching. Follow us on Twitter: @capcbristol

About the NIHR

The mission of the National Institute for Health Research (NIHR)is to improve the health and wealth of the nation through research. We do this by:

  • Funding high quality, timely research that benefits the NHS, public health and social care.
  • Investing in world-class expertise, facilities and a skilled delivery workforce to translate discoveries into improved treatments and services.
  • Partnering with patients, service users, carers and communities, improving the relevance, quality and impact of our research.
  • Attracting, training and supporting the best researchers to tackle complex health and social care challenges.
  • Collaborating with other public funders, charities and industry to help shape a cohesive and globally competitive research system.
  • Funding applied global health research and training to meet the needs of the poorest people in low and middle income countries.

NIHR is funded by the Department of Health and Social Care. Its work in low and middle income countries is principally funded through UK Aid from the UK government.

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