Antibiotic fails sinus infection test

Anyone who has felt the pressure of a weeklong sinus infection won’t be happy to hear it, but a study finds that a commonly prescribed medicine doesn’t clear up such attacks any better than the body does on its own.

The findings, in the Feb. 15 Journal of the American Medical Association, don’t apply to people who have chronic sinus infections lasting 28 days or more. But people with trademark signs of an acute sinus infection — yucky drainage, facial pressure, sore teeth, congestion and headache for a full week — overall fared no better with antibiotics than did people getting inert pills, scientists at Washington University in St. Louis report.

“This struck me as a very well-designed, -conducted and -analyzed study,” says James Hughes, an infectious disease physician at Emory University in Atlanta. “It adds to evidence [showing] that in most patients with acute sinus infections, antibiotics don’t add value.”

The researchers randomly assigned 166 adults with sinus infections to get either amoxicillin or a placebo three times a day for 10 days. All patients received other drugs for symptom relief as needed. Three days after treatment started, the two groups had improved at the same pace. Seven days out, slightly more patients getting antibiotics reported improvement, but this edge disappeared by day 10 when about four-fifths of each group reported “significant improvement” in their sinus infections, says study coauthor Jane Garbutt, a physician and researcher at Washington University.

James Gill, a practicing physician who also heads Delaware Valley Outcomes Research in Newark, Del., says the medical community has tried to slow the prescribing of antibiotics for sinus infections for years. “But I don’t think practice patterns have changed much,” he says. Doctors are under pressure from patients to do something, and telling them their symptoms are likely to resolve in a week or so rarely satisfies them, Gill says.

A big part of the problem is the sinuses’ inaccessibility, Hughes says. The bacteria that cause patients’ misery hole up and overproduce in the sinus cavities when they become blocked by excess mucus production, typically triggered by a respiratory infection. But culturing those holed-up bacteria is tricky, since readily obtained nasal microbes might be different from what’s growing farther in, Hughes says, which cannot be sampled without invasive techniques.

Without cultures, Garbutt says, targeting sinus infections with drugs is “a best guess.” Her team used amoxicillin since it is effective against Streptococcus pneumoniae, a common culprit in sinus infections. To make sure the drug had a good chance of working, the researchers obtained and tested simple nose swabs from children in the surrounding communities beforehand. They found little S. pneumoniae resistance to amoxicillin. Despite that, the antibiotic ultimately showed no benefit.

Gill says even the correct antibiotic often fails to knock out a sinus infection because the bacteria “are socked into closed spaces” in the sinuses, and the drugs just don’t reach them well.