Background: Acute rhinosinusitis is a common diagnosis in ambulatory practice and is associated with significant morbidity and lost time from work. Despite little evidence of any antibiotic benefit in this self-limiting disease, rhinosinusitis accounts for 20 percent of all antibiotic prescriptions for adults in the United States. With the threat of increasing antibiotic resistance, strong evidence of symptom relief is needed to justify the use of antibiotics in treating rhinosinusitis. Using disease-specific quality-of-life measures, Garbutt and colleagues evaluated the use of amoxicillin in adults with clinically diagnosed acute rhinosinusitis.

The Study: This randomized controlled trial enrolled patients 18 to 70 years of age from 10 community practices. Using diagnostic criteria for acute rhinosinusitis from the Centers for Disease Control and Prevention, eligible patients had persistent or worsening symptoms for seven to 28 days, or significantly worsening symptoms lasting less than seven days; purulent nasal discharge; and maxillary or tooth pain or tenderness. Symptom severity was rated as moderate, severe, or very severe. Exclusion criteria included very mild or mild symptoms, penicillin or amoxicillin allergy, antibiotic treatment within four weeks, impaired immunity, complications from sinusitis, or pregnancy. There were similar numbers of patients with a history of asthma, allergies, or sinus disease in each group, although there were significantly more smokers in the placebo group than in the amoxicillin group (26 versus 13 percent; P = .03).

The 166 patients were randomized to a 10-day course of amoxicillin, divided into three 500-mg doses per day, or an identical placebo regimen. Amoxicillin was chosen because it has a narrow spectrum and there was a low prevalence of amoxicillin-resistant Streptococcus pneumoniae in the community. Both groups were offered symptomatic treatment including acetaminophen, guaifenesin, dextromethorphan/guaifenesin, pseudoephedrine, and saline nasal spray. The modified Sinonasal Outcome Test-16, a validated tool that scores 16 sinus-related symptoms, was performed on days 3, 7, 10, and 28. Treatment compliance and satisfaction were assessed at day 10. The primary outcome was the effect of treatment on disease-specific quality of life at day 3, because the authors postulated that any benefit of antibiotic treatment would be evident after 48 to 72 hours of use.

Results: Eighty-five patients were randomized to the amoxicillin group and 81 to the placebo group. The mean changes in Sinonasal Outcome Test-16 scores were similar between the groups at days 3 and 10. No serious adverse effects were reported, although 11 participants in the amoxicillin group and 12 in the control group did not complete the 10-day course for reasons that included a lack of symptom improvement, worsening symptoms, improving symptoms, or adverse effects. Smoking, prior sinus infection, asthma, allergic rhinitis, duration of symptoms, and severity of symptoms were not associated with benefit from antibiotic therapy.

Conclusion: Amoxicillin did not improve symptoms in patients with clinically diagnosed uncomplicated acute rhinosinusitis.