Antibiotics for acute maxillary sinusitis

Sinusitis is one of the most common reasons for visiting a doctor and an estimated 20 million cases of acute sinusitis occur every year in the USA alone. There are four pairs of sinuses linked to the bony structures around the nose: maxillary, frontal, ethmoidal and sphenoidal sinuses. In sinusitis, these membrane-lined air spaces become infected, which causes pain and discharge from the nose. Treatment options include decongestants, steroid drops or sprays, mucus-clearing drugs (mucolytics), antihistamines and antibiotics and sometimes sinus puncture and irrigation for removal of purulent secretions.

In most cases sinusitis occurs during viral infections where antibiotics are ineffective, but the few cases that also have a bacterial infection (one or two out of every 100 patients with sinus symptoms) could benefit. Unfortunately it is difficult to distinguish between those who have a bacterial infection and those who do not. It is important to avoid unnecessary use of antibiotics and limit the potential for antibiotic resistance.

This updated review compiled data from 63 separate studies that used a variety of antibiotics for simple maxillary sinus infection, i.e. non-complicated acute sinusitis in a person with a healthy immune system. Nine of the studies compared antibiotics to placebo (1915 participants; seven of the studies conducted in primary care), and 54 studies compared different classes of antibiotics. Five of the nine placebo-controlled studies involving 1058 participants found that most participants got better within two weeks, regardless of whether they received the antibiotic or not (roughly 9 out of 10 participants in antibiotic groups and 8 out of 10 in placebo groups). Although all the five studies in this main outcome were assessed as having low risk of bias, the overall evidence was assessed only as being of moderate quality (it is possible that a new large study can change the estimate). In the remaining 54 studies comparing different antibiotics (10 different comparisons), no antibiotic was found to be superior to another. The evidence is current to March 2013.

The small benefit gained by antibiotics may be overridden by the negative effects of the drugs. In addition to patient-related adverse effects (like skin rash and gastrointestinal problems such as diarrhea, abdominal pain and vomiting), side effects include the risk of increased resistance to antibiotics amongst community-acquired pathogens (bacteria).

This review found that antibiotics will help some people a bit, but do not make a major difference to most people with acute maxillary sinusitis being treated in primary care.

Authors' conclusions: 

There is moderate evidence that antibiotics provide a small benefit for clinical outcomes in immunocompetent primary care patients with uncomplicated acute sinusitis. However, about 80% of participants treated without antibiotics improved within two weeks. Clinicians need to weigh the small benefits of antibiotic treatment against the potential for adverse effects at both the individual and general population levels.

Read the full abstract...

Sinusitis is one of the most common diagnoses among adults in ambulatory care, accounting for 15% to 21% of all adult outpatient antibiotic prescriptions. However, the role of antibiotics for sinusitis is controversial.


To assess the effects of antibiotics in adults with acute maxillary sinusitis by comparing antibiotics with placebo, antibiotics from different classes and the side effects of different treatments.

Search strategy: 

We searched CENTRAL 2013, Issue 2, MEDLINE (1946 to March week 3, 2013), EMBASE (1974 to March 2013), SIGLE (OpenSIGLE, later OpenGrey (accessed 15 January 2013)), reference lists of the identified trials and systematic reviews of placebo-controlled studies. We also searched for ongoing trials via and the WHO International Clinical Trials Registry Platform (ICTRP). We imposed no language or publication restrictions.

Selection criteria: 

Randomised controlled trials (RCTs) comparing antibiotics with placebo or antibiotics from different classes for acute maxillary sinusitis in adults. We included trials with clinically diagnosed acute sinusitis, confirmed or not by imaging or bacterial culture.

Data collection and analysis: 

Two review authors independently screened search results, extracted data and assessed trial quality. We calculated risk ratios (RRs) for differences between intervention and control groups in whether the treatment failed or not. All measures are presented with 95% confidence intervals (CIs). We conducted the meta-analyses using either the fixed-effect or random-effects model. In meta-analyses of the placebo-controlled studies, we combined data across antibiotic classes. Primary outcomes were clinical failure rates at 7 to 15 days and 16 to 60 days follow-up. We used GRADEpro to assess the quality of the evidence.

Main results: 

We included 63 studies in this updated review; nine placebo-controlled studies involving 1915 participants (seven of the studies clearly conducted in primary care settings) and 54 studies comparing different classes of antibiotics (10 different comparisons). Five studies at low risk of bias comparing penicillin or amoxicillin to placebo provided information on the main outcome: clinical failure rate at 7 to 15 days follow-up, defined as a lack of full recovery or improvement, for participants with symptoms lasting at least seven days. In these studies antibiotics decreased the risk of clinical failure (pooled RR of 0.66, 95% CI 0.47 to 0.94, 1084 participants randomised, 1058 evaluated, moderate quality evidence). However, the clinical benefit was small. Cure or improvement rates were high in both the placebo group (86%) and the antibiotic group (91%) in these five studies. When clinical failure was defined as a lack of full recovery (n = five studies), results were similar: antibiotics decreased the risk of failure (pooled RR of 0.73, 95% CI 0.63 to 0.85, high quality evidence) at 7 to 15 days follow-up.

Adverse effects in seven of the nine placebo-controlled studies (comparing penicillin, amoxicillin, azithromycin or moxicillin to placebo) were more common in antibiotic than in placebo groups (median of difference between groups 10.5%, range 2% to 23%). However, drop-outs due to adverse effects were rare in both groups: 1.5% in antibiotic groups and 1% in control groups.

In the 10 head-to-head comparisons, none of the antibiotic preparations were superior to another. However, amoxicillin-clavulanate had significantly more drop-outs due to adverse effects than cephalosporins and macrolides.