Tuesday, September 29, 2009

Antibiotics, sinusitis, and swine flu

For the past few months, the Giant supermarket chain has offered a free supply of certain antibiotics to customers with a doctor's prescription. As a family physician who is always explaining to patients why antibiotics are ineffective for the common cold, I wish that Giant executives had chosen a more useful class of drug to promote: drugs for high blood pressure or diabetes, for example. While doctors in past years (and, unfortunately, many doctors practicing today) handed out antibiotics like candy, recent scientific studies have shown how limited the medical uses of these drugs really are.

Take sinus infections, for example. They're sometimes caused by bacteria, so antibiotics should help, right? And some studies have in fact suggested that a few patients with laboratory-proven bacterial sinusitis may recover more quickly with antibiotics. But since tests for bacterial sinusitis are not available in primary care practices, it would be useful to identify clinical findings associated with a positive response to antibiotics. In a 2006 study published in the Annals of Family Medicine, Dr. An De Sutter and colleagues at Ghent University in Belgium studied the utility of clinical signs and symptoms of sinusitis and sinus x-rays for predicting duration of illness and the effect of amoxicillin, a commonly prescribed antibiotic.

The study enrolled 300 patients age 12 and older who visited their family physician with signs or symptoms suggestive of a sinus infection. Patients were randomized to take 10 days of either amoxicillin or a sugar pill. No clinical sign, symptom, or x-ray finding had any relationship to duration of illness or response to amoxicillin. The authors concluded that clinical information cannot be used to select patients who would benefit from antibiotic treatment. Consequently, they recommended symptomatic treatment (e.g. over-the-counter pain medication, nasal decongestants), rather than antibiotics, for patients with sinus infections. And so do I.

You may also wonder what you should do if you think you may have the H1N1 (also known as "pandemic" or "swine") flu. The Centers for Disease Control and Prevention has put together a nice web page that answers the most commonly asked questions. When an H1N1 flu vaccine is available next month, it is especially important that pregnant women and young children are at the head of the line, since they are the most likely to become very sick if they get the flu.