Prescribing amoxicillin for a cough in the absence of suspected pneumonia may do more harm than good, according to Swiss researchers. Physicians and patients should generally refrain from antibiotic use, according to study results.

Researchers at the Kantonsspital Aarau in Switzerland randomly assigned more than 2,000 adults complaining of a cough to take either the antibiotic amoxicillin for a week or an inactive placebo.

They discovered the antibiotic was no more effective at relieving symptoms or their duration than the placebo. The findings also held among people who were older than 60.

The authors did note that more people in the placebo group did experience new or worsening symptoms, but that did not occur frequently enough to justify treating everyone with antibiotics. According to the research, for ever 30 people treated, only one would benefit from the prevention of new or worsening symptoms.

“The main message here is that antibiotics are usually not necessary for respiratory infections, if pneumonia is not suspected,” said Philipp Schuetz, MD, MPH, of the Kantonsspital Aarau in Switzerland. “Only a few patients benefit from antibiotics and these may be identified with new blood tests for bacterial infections.”