A 40-year-old woman presents with nasal congestion and purulent discharge for one week, with no improvement despite the use of over-the-counter medications. There is tenderness upon palpation over the maxillary sinuses.
Should antibiotics be prescribed for acute maxillary sinusitis?
Although there is some evidence that antibiotics are effective in the treatment of acute uncomplicated sinusitis, this benefit is modest. Most patients with acute sinusitis improve within two weeks without antibiotics. The potential risk of adverse effects from antibiotics may outweigh the benefits of therapy.
Although most sinusitis is viral, antibiotics are widely prescribed for acute sinusitis. It is more likely to be bacterial if symptoms or signs of acute rhinosinusitis are present 10 days or more beyond the onset of upper respiratory symptoms, or if signs and symptoms worsen within 10 days after an initial improvement. Viral or bacterial sinusitis can be treated with watchful waiting and symptomatic relief.1
The Cochrane review included two categories of trials: antibiotics versus placebo and antibiotic versus antibiotic.2 Six trials compared antibiotics with placebo, with a total of 747 adult participants. The antibiotics studied included penicillin V, amoxicillin, and azithromycin (Zithromax). Five of the trials were reported as double-blinded. Patients were recruited based on clinical symptoms lasting longer than seven days in five of the studies, and radiography with plain film or computed tomography was used to confirm diagnosis in four studies. The number needed to treat (NNT) with antibiotic therapy to prevent one clinical failure was 14. However, cure or improvement rates were high in the antibiotic and placebo groups (90 versus 83 percent, respectively). When evaluating treatment with antibiotics versus placebo for three to five days, the outcomes of cure or improvement were inconsistent.
Adverse effects of antibiotics were common, ranging from 8 to 59 percent with penicillin and 23 to 56 percent with amoxicillin. The most common reported effects included diarrhea, abdominal pain, vomiting, and skin rash.
A total of 51 studies were used to compare different classes of antibiotics in the treatment of acute sinusitis. A statistically significant difference in overall effectiveness was not found, with the exception of amoxicillin/clavulanate (Augmentin), which had a significantly lower failure rate at seven to 15 days compared with cephalosporins (n = 1,891; risk ratio = 1.38; 95% confidence interval, 1.04 to 1.82).
Another recent meta-analysis came to a similar conclusion.3 The authors found that antibiotics, when compared with placebo, provide a higher rate of cure and faster improvement in symptoms from acute sinusitis, but that the benefit was of only modest clinical significance (n = 2,547; NNT = 15). They also found that antibiotics were associated with significantly more adverse effects. The authors concluded that a policy of universal prescribing of antibiotics for patients with acute sinusitis could not be endorsed, and that physicians should weigh each case individually and prescribe antibiotics when a bacterial etiology is more likely (i.e., longer duration of symptoms or more severe symptoms).
In summary, available evidence does not support the broad clinical practice of prescribing antibiotics for acute sinusitis because the benefit of antibiotics is small and must be balanced with the risk of adverse effects. More high-quality placebo-controlled trials are needed, not only to assess the effectiveness of antibiotics, but also to determine standard diagnostic criteria to guide physicians in clinical practice. Other important considerations needing further study include assessing the potential risks for antibiotic resistance at the population level, assessing appropriate treatment duration if antibiotics are used, and determining which subgroups of patients might benefit most from antibiotic therapy.
Background: Expert opinions vary on the appropriate role of antibiotics for sinusitis, one of the most commonly diagnosed conditions among adults in ambulatory care.
Objectives: The authors examined whether antibiotics are effective in treating acute sinusitis, and if so, which antibiotic classes are the most effective.
Search Strategy: The authors searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, 2007, Issue 3), Medline (1950 to May 2007), and EMBASE (1974 to June 2007).
Selection Criteria: The authors selected randomized controlled trials comparing antibiotics with placebo or antibiotics from different classes for acute maxillary sinusitis in adults. Included were trials with clinically diagnosed acute sinusitis, whether or not confirmed by radiography or bacterial culture.
Data Collection and Analysis: At least two review authors independently screened search results, extracted data, and assessed trial quality. Risk ratios (RRs) were calculated for differences in the intervention and control groups to see if the treatment was a failure. In meta-analyzing the placebo-controlled studies, the data across antibiotic classes were combined. Primary outcomes were the clinical failure rates at seven to 15 days and 16 to 60 days follow-up.
Main Results: The review included 57 studies (six placebo-controlled studies and 51 studies comparing different classes of antibiotics). Five studies involving 631 participants provided data for comparison of antibiotics to placebo, in which clinical failure was defined as a lack of cure or improvement at seven to 15 days follow-up. These studies found a slight statistical difference in favor of antibiotics, compared with placebo, with a pooled RR of 0.66 (95% confidence interval [CI], 0.44 to 0.98). However, the clinical significance of the result is equivocal, considering that cure or improvement rate was high in the placebo group (80 percent) and the antibiotic group (90 percent). Based on six studies, in which clinical failure was defined as a lack of total cure, there was significant difference in favor of antibiotics compared with placebo, with a pooled RR of 0.74 (95% CI, 0.65 to 0.84) at seven to 15 days follow-up. None of the antibiotic preparations were superior to another.
Authors' Conclusions: Antibiotics have a small treatment effect in patients with uncomplicated acute sinusitis in a primary care setting with symptoms for more than seven days. However, 80 percent of participants treated without antibiotics improved within two weeks. Physicians need to weigh the small benefits of antibiotic treatment against the potential for adverse effects at the individual and general population level.
These summaries have been derived from Cochrane reviews published in the Cochrane Database of Systematic Reviews in the Cochrane Library. Their content has, as far as possible, been checked with the authors of the original reviews, but the summaries should not be regarded as an official product of the Cochrane Collaboration; minor editing changes have been made to the text (http://www.cochrane.org).