US scientists researching treatments for sinus infections suggest that antibiotics are overprescribed to treat the condition. And they are concerned this could be increasing the drug resistance and virulence of infectious bacteria.

The study is published in the March issue of Archives of Otolaryngology-Head & Neck Surgery.

According to the study, by Hadley J. Sharp and colleagues at the University of Nebraska Medical Center, Omaha, US, antibiotics were prescribed for 82 per cent of acute sinus infections and nearly 70 per cent of chronic sinus infections.

This is surprising because most sinus infections are caused by viruses, and antibiotics only kill bacteria.

The scientists used national data from 1999 and 2002 to find out which drugs were being prescribed for sinus infections by general practitioners, outpatient and emergency departments. The data was representative of the US population and came from two national surveys collected by the National Center for Health Statistics.

Rhinosinusitis, commonly known as sinus infection or sinusitis, is an inflammation of the sinus cavities that connect with the nasal passage. According to the study, it is a common and expensive medical condition in the US.

Acute sinusitis occurs for up to 4 weeks and is thought to be caused mostly by infectious agents. Chronic sinusitis is thought to be affected mostly by allergies, hormone changes and facial anatomy and symptoms persist for 12 or more weeks.

In 2002, of all the antibiotic prescriptions that year in the US, 21 per cent were for adults with sinus infections and 9 per cent was for children.

According to the survey data, over 14 million visits are paid to health care facilities in the US every year are for chronic sinusitis, while over 3 million are for acute sinusitis. As a proportion of all ambulatory care in the US per year, chronic sinusitis represents 1.39 per cent of visits and acute sinusitis 0.30 per cent.

In 69.95 percent of visits for chronic sinusitis at least one antibiotic was prescribed. For acute sinusitis this figure was 82.74 per cent.

Sharp and colleagues assessed that “The most frequently recommended medications for treatment of both acute and chronic rhinosinusitis are antibiotic agents, followed by antihistamines; nasal decongestants; corticosteroids; and antitussive, expectorant and mucolytic agents, respectively”.

The most commonly used antibiotics for both chronic and acute bacterial infections were penicillins (mainly amoxicillin and amoxicillin-clavulanate potassium, brand name Augmentin). These were prescribed appropriately, they said, with 30.35 per cent of chronic and 27.18 per cent of acute infection visits mentioning penicillin prescriptions.

However, the researchers questioned the use of the stronger antibiotics such as erythromycins, lincosamides, and macrolides, amongst others. These were mentioned in 24.32 per cent of acute sinusitis visits, which, in order, makes them more frequently prescribed than cephalosporins, sulfonamides and trimethprim, and tetracyclines.

The authors assessed the relative proportions of the causes of sinusitis from other studies. Comparing these proportions with the relative proportions of what is actually being prescribed to treat sinusitis they found major discrepancies.

They concluded that “Prescription antibiotic drugs are being used far more than bacterial causes studies would indicate.”

Sharp and colleagues also assessed that “Nasal and inhaled corticosteroids are prescribed more frequently to treat acute rhinosinusitis than published studies imply is necessary”.

However, they estimated that where antihistamines were prescribed, this was roughly in proportion with estimated prevalence of allergic sinusitis.

In trying to fathom why the use of antibiotics is so high, the authors suggest that some doctors could be trying to treat secondary infections. On the other hand, it could be because doctors think antibiotics are working because patients get better while taking them, whereas they could be getting better anyway.

They express concern about the problems that overuse of antibiotics bring, including drug resistance and increased virulence of bacteria.

They conclude, “When two-thirds of patients with sinus symptoms expect or receive an antibiotic and as many as one-fifth of antibiotic prescriptions for adults are written for a drug to treat rhinosinusitis, these disorders hold special pertinence on the topic.”

“Treatment of Acute and Chronic Rhinosinusitis in the United States, 1999-2002.”
Hadley J. Sharp, David Denman, Susan Puumala, Donald A. Leopold.
Arch Otolaryngol Head Neck Surg. 2007;133:260-265.
Vol. 133 No. 3, March 2007

Click here for Abstract.

Click here for Sinusitis Fact Sheet for patients (from US National Institutes of Health).

Written by: Catharine Paddock
Writer: Medical News Today