Antibiotics should not used to treat a runny nose

Antibiotics should not be given to patients with acute purulent rhinitis (a runny nose with coloured discharge), a familiar feature of the common cold, concludes a study published on the British Medical Journal website.

General practitioners often prescribe antibiotics for respiratory tract infections when nasal discharge is purulent. Most guidelines recommend against their use for this condition, but this advice is based on one study that showed no effect.

So researchers in New Zealand searched the scientific literature for trials comparing antibiotics with placebo for acute purulent rhinitis (duration less than 10 days).

They identified seven trials. Pooling the results showed that antibiotics for acute purulent rhinitis may be beneficial. The numbers needed to treat ranged from 7 to 15, meaning that, at best, six patients get no benefit for every one who gets benefit.

Harms attributed to antibiotics were mainly vomiting, diarrhoea, and abdominal pain, but also included rashes and hyperactivity. The numbers needed to harm ranged from 12 to 78.

No serious harm occurred in the placebo arm in any of the trials. This fits with the medical view that this is not a serious condition, write the authors.

Antibiotics are probably effective for acute purulent rhinitis, say the authors. They can cause harm but most patients will get better without antibiotics.

So, although these findings differ from the guidelines in terms of the effectiveness of antibiotics for acute purulent rhinitis, the authors support the current "no antibiotic as first line" advice and suggest that antibiotics should be used only when symptoms have persisted for long enough to concern parents or patients.