Antibiotics no Better than Placebo Against Acute Rhinosinusitis

Abstract & Commentary

By Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Associate Chief of Infectious Diseases, Santa Clara Valley Medical Center, Editor for Infectious Disease Alert.

This article originally appeared in the March issue of Infectious Disease Alert. At that time it was peer reviewed by Timothy Jenkins, MD, Assistant Professor of Medicine, University of Colorado, Denver Health Medical Center. Dr. Jenkins reports no financial relationships relevant to this field of study. Dr. Deresinski does research for the National Institutes of Health, and is an advisory board member and consultant for Merck.

Synopsis: In a double-blind, randomized clinical trial, amoxicillin therapy did not improve outcomes in patients with clinically diagnosed acute rhinosinusitis.

Source: Garbutt JM, et al. Amoxicillin for acute rhinosinusitis: A randomized controlled trial. JAMA 2012;307:685-692.

Garbutt and colleagues performed a randomized, placebo-controlled trial designed to evaluate the efficacy of antibiotic therapy in patients with a clinical diagnosis of acute rhinosinusitis at 10 primary care practices in St. Louis. The diagnosis required a history of maxillary pain or tenderness felt in the face or teeth, purulent nasal discharge, with symptoms present for > 7 days and < 28 days. Also eligible were patients who were symptomatic for less than 7 days but had a history of improvement followed by worsening of symptoms. A total of 166 patients were randomized to receive either 500 mg amoxicillin or placebo, each three times daily for 10 days. Patients were also provided a 5-7 day supply of acetaminophen, guaifenesin, dextromethorphan, pseudoephedrine, and 0.65% saline nasal spray. The primary outcome of the study was the effect of treatment on disease-specific quality of life at day 3 as determined by the change in their Sinonasal Outcome Test-16 (SNOT-16) score, a validated measure examining 16 symptoms for which the minimally important difference is 0.5 on a scale ranging from 0 to 3.

There was no significant difference in SNOT-16 score at day 3 (mean difference, 0.03) nor on day 10 (mean difference, 0.01). At day 7, however, the difference favored amoxicillin therapy (mean difference, 0.19; 95% confidence interval, 0.024 to 0.35), but this difference is not considered clinically important. In a retrospective assessment of symptoms, a similar pattern held, with no significant difference at days 3 and 10, but greater improvement in the amoxicillin recipients at day 7 (74% vs 56%; P = 0.02).

Commentary

The most recent national guidelines were published last year by a Canadian group (new IDSA guidelines are in a late stage of development).1 They recommend first- line treatment with amoxicillin for patients with a clinical diagnosis of acute bacterial rhinosinusitis who have severe disease and or comorbidities and for whom quality of life and/or productivity may be improved.

However, this study does not provide support for the use of antibiotics in the treatment of clinically diagnosed acute sinusitis in adult outpatients. This is consistent with a number of studies that have, at best, demonstrated minimal benefit of antibiotics in similar patients. Analysis of such studies are, of course, complicated by the fact that the clinical diagnosis of acute sinusitis is generally inaccurate and that the symptoms often cannot be distinguished from those of viral upper respiratory infections which frequently involve the paranasal sinuses. Viral upper respiratory infections are, of course, remarkably common, estimated to occur 2-5 times yearly in adults. Most symptoms from these infections peak at day 2 or 3 (the time of analysis of the primary outcome in this study) but may take as long as 14 days to totally resolve. It is true, however, that 0.5%-2.0% are estimated to be complicated by bacterial superinfection. Bacterial infection is suggested in patients with symptoms persisting for 10 days or more and/or showing a pattern of initial improvement followed by worsening.

Almost all the patients in this study used the package of symptomatic treatments they were provided. Thus, it is possible that resolution of some bacterial infections were accelerated by establishment of drainage of the sinus cavity. Since microbiologic specimens were not obtained in this study, it is possible that some infections were caused by amoxicillin-resistant bacteria. Nonetheless, it must be accepted that this study demonstrated no significant benefit with antibiotic therapy.

Reference

1. Desrosiers M, et al. Canadian clinical practice guidelines for acute and chronic rhinosinusitis. Allergy Asthma Clin Immunol 2011;7:2.