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Shorter courses of antibiotics (amoxicillin) are as effective as longer courses for treating pneumonia in children. In a new study, 3 days of antibiotic were as good as 7 days; and a lower dose as good as a higher dose. These findings could reduce the total dose of antibiotics taken by children with this illness.

Pneumonia is one of the most common serious bacterial infections in children. But the most effective duration and dose of antibiotics is unclear.

Antibiotics should only be used when they are effective – and at the lowest dose for the shortest course. Bacteria can become resistant to antibiotics and difficult to treat. Using antibiotics more sparingly slows the development of resistant bacteria.

This study included children with pneumonia outside of hospital (community-acquired pneumonia, CAP). Children received either a high or low dose of amoxicillin (a type of penicillin), for either 3 or 7 days.

The shorter duration and lower dose were both effective, although children on the 3 day course coughed for slightly longer. The researchers hope their findings will reduce unnecessary exposure to antibiotics and slow the development of antibiotic-resistant bacteria.

Further information about pneumonia and about antibiotic resistance is available on the NHS website.

What’s the issue?

Antibiotics are commonly used to treat people with bacterial infections, especially those at risk of complications. They should only be used when they are essential because bacteria can become resistant to antibiotics. Using less antibiotics slows the development of this resistance and helps ensure that antibiotics remain effective.

Pneumonia is a serious infection of the lungs. People with pneumonia often cough, have a high temperature (of 38C or higher), and sometimes have difficulty breathing.

Since 2010, most children in the UK have been vaccinated against the bacteria, Streptococcus pneumoniae, which is the main cause of pneumonia. This has reduced the numbers with pneumonia but has not reduced the number of children admitted to hospital with the condition. Many are, however, discharged quickly.

There are limited data on the ideal dose and duration of antibiotics for pneumonia in children. The National Institute for Health and Care Excellence (NICE) recommends a 5 day course in children aged 1 - 4 years. The World Health Organization (WHO) recommends a 3 day course; guidelines across Europe vary between 5 and 10 days. The British Thoracic Society recognises that there are few robust studies on the best duration and dose of treatment.

Researchers looked at the effectiveness and safety of a 3 and 7 day course of amoxicillin at high and low doses in children with pneumonia. They explored how different durations and doses affected bacterial resistance to penicillin.

What’s new?

The study included 814 children who developed pneumonia in the community (CAP) and were admitted to hospital. They were treated at 29 hospitals in the UK and Ireland. All were older than 6 months (average age was 2.5 years) and were due to receive only amoxicillin (oral syrup) after they went home.

When children were discharged from hospital, they were randomly put into groups which received different courses of amoxicillin to take at home. They took either a low dose (35-50 mg/kg/day) or a high dose (79-90 mg/kg/day) of amoxicillin. They either took the syrup for 7 days (long course) or for 3 days (short course) with dummy treatment (placebo) for the remaining 4 days. These does and durations of treatment are commonly given to children in the UK who have been hospitalised with pneumonia.

To assess the effectiveness of each treatment strategy, researchers looked at whether a second antibiotic was needed within 28 days. This was the main outcome of the trial but duration of symptoms and frequency of side effects were also considered.

They found that, regardless of antibiotic dose and duration:

  • around 1 in 8 children in each group was prescribed a second antibiotic; there was no difference between the groups
  • most other symptoms (including fever and wheeze) lasted the same length of time in all groups; the only slight difference was in cough (12 days with the short course, and 10 days with the long course)
  • adverse events (including rash, thrush and diarrhoea) were the same in each group.  

To check for signs of penicillin resistance, the researchers collected nose and throat swabs from just over half the children. They compared swabs taken before treatment with those at day 28 and did not find signs of antibiotic resistance related to duration or dose of antibiotic.

Why is this important?

A 3 day course of amoxicillin was as effective as a 7 day course for treating children with pneumonia. Children on the short course had a mild cough for longer than those on the long course, but the cough did not interfere with the child’s normal activities.

This finding may prompt more widespread use of short courses of antibiotics for children with pneumonia. This will reduce the use of antibiotics, which is needed to prevent antibiotic resistance and help ensure that antibiotics remain effective.

The low dose was as effective as the high dose. But the researchers caution that the effective dose depends on whether bacteria are resistant to antibiotics. This finding might be more difficult to implement in practice especially in countries which have higher levels of antibiotic resistance than in the UK.

What’s next?

The researchers hope their findings will guide prescribing advice in the UK and lead to routine use of the short course. Many children do not like taking antibiotics; both parents and children may welcome the short course.

This study did not find an increase in bacteria (pneumococci) resistant to penicillins in the nose and throat. The researchers caution that resistant bacteria may have been developing elsewhere in the body. Other bacteria (not examined in this study) could have developed resistance. The researchers are carrying out laboratory studies to explore the impact of amoxicillin dose and duration on the development of resistance in other bacteria.

This study did not include severely ill children who needed to be treated in hospital for more than 2 days, or who needed multiple antibiotics. Children with other long-term conditions were also excluded. The findings may therefore not apply to these groups of children.

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This Alert was based on: Barratt S, and others. Amoxicillin duration and dose for community-acquired pneumonia in children: the CAP-IT factorial non-inferiority RCT. Health Technology Assessment 2021;25:60.

Video summarising the findings:

Funding: This study is funded by the NIHR's Health Technology Assessment programme.

Conflicts of Interest: Several authors reported competing interests.

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

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