Study Question: Is amoxicillin-clavulanate effective in the treatment of acute sinusitis?

Setting: Outpatient (any)

Study Design: Randomized controlled trial (double-blinded)

Synopsis: Sinusitis is a tricky diagnosis; distinguishing sinus infection from rhinitis can be difficult. Moreover, a good proportion of patients with sinusitis have a viral infection. This study evaluated the role of antibiotics in the treatment of 252 adults with a clinical diagnosis of rhinosinusitis. The patients had a history of repeated purulent nasal discharge and maxillary or frontal sinus pain for at least 48 hours (but less than one month). In addition, all had pus documented by rhinoscopy.

Participants were enrolled consecutively using central randomization (allocation concealed). All of the patients received a topical nasal decongestant and acetaminophen, in addition to placebo or amoxicillin-clavulanate in a dosage of 875 mg/125 mg (amoxiclav) twice daily for six days. The primary outcome—time to cure—was no different between the groups treated with amoxiclav compared with placebo (five versus four days). Cure rates at one week (30 percent) and two weeks (75 percent) were similar between the groups. The two treatment groups did not differ in the number of days of restricted activity.

One patient in the placebo group died of a brain abscess. Diarrhea was almost four times as likely in the amoxiclav group at one week (odds ratio [OR], 3.89; 95 percent confidence interval [CI], 2.09 to 7.25) and still higher at two weeks (OR, 1.71; 95 percent CI, 0.91 to 3.23). The study was large enough to find a 50 percent increase in cure rate, assuming a spontaneous cure rate of 60 percent. Smaller differences may not have been identified.

Bottom Line: In patients diagnosed with acute sinusitis in general practice, a broad-spectrum antibiotic does not relieve symptoms faster than placebo. As expected, adverse effects were higher in the patients taking the antibiotic. (Level of Evidence: 1c)