Children suffering from a common cold and persistent runny noise should not be treated initially with antibiotics, researchers said on Friday.

They suggested antibiotics, which can sometimes cause side effects such as vomiting, diarrhea and abdominal pain, should only be prescribed if the youngsters do not improve.

"Most patients will get better without antibiotics," Bruce Arroll of the University of Auckland in New Zealand said in a report in the British Medical Journal.

The overuse of antibiotics has lead to concerns about the emergence of so-called superbugs that are resistant to the most powerful antibiotics.

Arroll and his colleague Tim Kenealy reviewed seven studies that looked at the effectiveness or harm of treating acute purulent rhinitis, a runny nose with a colored discharge, with antibiotics.

Although the drugs are probably effective for the problem, they found that for each patient that will benefit from the drugs six others will not.

"Our summation would be to suggest initial management by non-antibiotic treatments or "watchful waiting" and that antibiotics should be used only when symptoms have persisted for long enough to concern parents or patients," they said in the report.

The researchers said their findings support current "no antibiotic as first line" advice.