Children with lower respiratory tract infections have similar severity and duration of symptoms whether or not they receive antibiotics, results of a randomized placebo-controlled trial show.

Researchers randomized children six months to 12-years-old presenting in primary care with acute uncomplicated lower respiratory infections to receive amoxicillin 50 mg/kg per day (n=221) or an oral suspension placebo (n=221) for seven days.

The median duration of moderately bad or worse symptoms was similar with antibiotics and placebo (five days vs six days), researchers report in The Lancet. At the end of the seven days, there were also no significant differences in the proportions of children with abnormal chest signs (35 percent on antibiotics vs 34 percent on placebo), fever (80 percent vs 70 percent), sputum or chest rattle (78 percent vs 74 percent), or shortness of breath (47 percent vs 45 percent).

These results suggest that antibiotics should not be used for uncomplicated acute lower respiratory tract infections, said lead study author Paul Little of the Primary Care Population Sciences and Medical Education Unit at the University of Southampton in the UK.

“Antibiotic treatment is reasonable when clinicians suspect pneumonia or when the child’s immune system is compromised,” Little said by email. Otherwise, it’s not indicated for these patients, Little stressed.

Part of the reason antibiotic prescriptions persist for uncomplicated pediatric lower respiratory tract infections is that symptoms can be long-lasting and both parents and clinicians can have unrealistic expectations for how quickly symptoms should resolve, Little said.

Unfortunately, widespread use of antibiotics can have the unintended consequence of reinforcing the misperception that this intervention works, Little added.

“Children get antibiotics, the illness settles but parents attribute the recovery to antibiotics when in fact it was just the natural history, and the message gets out there for those parents and in the wider society that antibiotics work for chest infections,” Little said.

One limitation of the study is that researchers lacked data on whether parents dispensed the entire seven-day course of antibiotics as prescribed, the authors note. It’s also possible that results from use of amoxicillin – chosen because it’s the most commonly prescribed in the UK for this indication – might not reflect outcomes with other antibiotics.

Even so, the results offer fresh evidence in support of less intervention, including less use of antibiotics, for children with lower respiratory tract infection, write Dr. Rianne Oostenbrink of the department of general pediatrics at Erasmus MC-Sophia in Rotterdam, The Netherlands, and Lina Jankauskaite of the Lithuanian University of Health Sciences, in Kaunas, in a commentary accompanying the study.

“A notable finding of this study is that only a few children had moderately bad or worse symptoms by day 14, and antibiotics did not alleviate the symptoms compared with placebo,” they write. “Additionally, this trial aligns with other studies that have shown that reducing antibiotic treatment for lower respiratory tract infection is not associated with prolonged morbidity or higher incidence of complications.”

Oostenbrink didn’t respond to emails seeking further comment.