Doctors should ease off prescribing antibiotics for sinus infections, even if the symptoms have lasted for longer than seven to ten days, a new meta-analysis has concluded.

The study, published in The Lancet by researchers from Europe and the US led by Dr Jim Young of the Basel Institute for Clinical Epidemiology in Switzerland, adds weight to the continuing efforts in the UK and other countries to curb over-zealous prescribing of antibiotics that contributes to the rapid spread of drug-resistant bacteria.

Antibiotics are prescribed in an estimated 80% of cases of presumed acute rhinosinusitis in the US. The corresponding prescribing rates in Europe are 72-92%. As Dr Young et al point out, primary-care physicans continue to overprescribe antibiotics in these circumstances because the distinction between viral and bacterial sinus infection is hard to make. An added difficulty is that patients often come in expecting antibiotics for sinus infections.

The researchers identified suitable clinical trials in which adult patients with rhinosinusitis-like complaints were randomly assigned to treatment with an antibiotic or a placebo. Individual patient data from 2,547 adults in nine trials were re-analysed to assess the overall impact of antibiotic treatment and the prognostic value of common signs and symptoms by calculating the number needed to treat (NNT) with antibiotics if one additional patient with acute rhinosinusitis were to be rid of the condition.

The meta-analysis found that 15 patients with rhinosinusitis-like symptoms would need to be given antibiotics before one extra patient were cured (95% confidence internal (CI) NNT [benefit] 7 to NNT [harm] 190). Patients with a purulent discharge (i.e., pus) in the pharynx took longer to cure than those without this symptom: the NNT for patients with purulent discharge was eight before an additional patient could be cured (95% CI NNT [benefit] 4 to NNT [harm] 47).

Patients who were older, reported symptoms for longer, or reported more severe symptoms also took longer to cure but were no more likely to benefit from antibiotics than other patients, the authors noted.

They concluded that common clinical signs and symptoms are not an accurate way of identifying patients with rhinosinusitis for whom antibiotic treatment is clearly justified. Antibiotics are not even warranted if the patient reports symptoms of more than 7-10 days’ duration, the researchers added.

“The implication for primary care is that antibiotics offer little benefit for patients with acute rhinosinusitis-like complaints,” the authors commented. “Although our results do not apply to children or to patients with a suppressed immune system, they should reassure physicians that only watchful waiting and symptomatic relief are warranted for most adult with acute rhinosinusitis-like complaints.”

The UK’s National Institute for Health and Clinical Excellence (NICE) recently published for consultation a draft guideline on the prescribing of antibiotics for self-limiting respiratory tract infections in primary care.

It recommended generally negotiating a “no antibiotic” or a “delayed antibiotic” prescribing strategy for patients with conditions including acute sinusitis.