Southampton researchers have found that the antibiotic amoxicillin is only slightly more effective at treating chest infections in children than taking no medication.
The largest trial of amoxicillin in children identified only a small difference in the length of symptoms.
The findings, published in The Lancet, have prompted further warnings about the overuse of antibiotics in primary care.
The NIHR-funded study was led by researchers from Southampton. It was supported by centres at the Universities of Bristol, Oxford and Cardiff.
Small difference in symptoms
Chest infections in children are one of the most common acute illnesses treated in primary care in developed countries.
Research 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.
The new trial recruited 432 children aged six months to twelve years old with acute uncomplicated chest infections from primary care practices in England and Wales.
Participants were randomly assigned to receive either amoxicillin or a placebo three times a day for seven days.
Children given the placebo had symptoms that were rated moderately bad or worse for around six days on average after seeing the doctor, and those given antibiotics got better only 13 percent quicker.
Increasing antibiotic resistance
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 amoxicillin 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.”