I pride myself on judicious use of antibiotics for acute upper respiratory infections (URIs). The easy patients to treat are those with classic viral symptoms of clear rhinorrhea, nonproductive cough, and a mild to moderate illness of short duration. Most of these patients readily accept my reassurance and advice for symptomatic treatment.
Patients with acute bronchitis are a bit tougher to treat. They often have productive cough and are moderately ill for a longer duration. Even though antibiotics are of marginal, if any, benefit for acute bronchitis,1 approximately 30% of my patients receive an antibiotic prescription despite my best efforts to the contrary. I usually resort to the popular last-ditch tactic of the backup prescription. If 50% of my patients fill those backup prescriptions as Couchman and colleagues2 found, my actual prescribing rate for acute bronchitis is only 15%—not bad for this largely viral syndrome.
The good news is that the anti-antibiotic scuffle with patients may be happening less often. The public campaign by the Centers for Disease Control and Prevention to reduce inappropriate use of antibiotics appears to be reaching some of my patients. They are more likely to accept my advice for symptomatic treatment than they were 5 years ago. However, there is still a great need for educating patients and physicians about appropriate use of antibiotics for respiratory tract infections, as illustrated by the survey of college students by Zoorob and colleagues3 in this issue of JFP. When confronted with scenarios typical of viral URIs, 50% of those bright young adults would seek medical care and an antibiotic prescription.
Antibiotics for Acute Sinusitis
Acute sinusitis is a horse (or discharge, maybe?) of a different color. I used to think that sinusitis was the easy one to handle. Cheek pain plus green discharge equals antibiotic. The patient goes away satisfied, and I go on to the next coughing patient. Not so fast. This last port of refuge for antibiotic advocates is crumbling, too. Consider the following sobering facts:
Sinusitis rarely occurs in isolation and is most often accompanied by nasal cavity inflammation, resulting in the new designation rhinosinusitis.4
Most cases of rhinosinusitis are caused by viruses. Maxillary sinus radiographs of young adults with typical viral URIs showed mucosal abnormalities in 39% of cases on the seventh day of illness,5 and computed tomography (CT) scans were abnormal in 87% of similar cases.6
When based on signs and symptoms, the diagnosis of acute sinusitis is correct in approximately 50% or less of cases.7-11 We probably are not this accurate in routine practice.
Randomized clinical trials of antibiotic treatment of rhinosinusitis have shown no effect when the diagnosis was based on clinical findings alone12 or on clinical findings confirmed by plain radiographs.13
Despite the negative results of these randomized clinical trials, more than 90% of patients with a diagnosis of sinusitis by primary care physicians receive an antibiotic prescription.13,14
Antibiotics have little effect on the course of rhinosinusitis, because the clinical diagnosis of bacterial sinusitis is so difficult. The signs and symptoms of viral infection of the paranasal sinuses mimic those of bacterial infection. Several investigators have attempted to identify clinical findings specific to bacterial sinusitis using a high-quality reference standard (sinus puncture and aspiration of purulent secretions, positive bacterial culture of aspirated secretions, or positive CT scan of the sinuses).7,8,11 Maxillary facial pain, tooth pain, and purulent nasal discharge (ie, white, not green) are most discriminating, but even with these seemingly specific findings the ability to diagnose bacterial sinusitis accurately is poor. Because viral rhinosinusitis and rhinosinusitis with minimal bacterial suprainfection are so much more common than significant bacterial sinusitis, the few truly antibiotic-responsive bacterial infections are diluted out in clinical trials. We therefore see no effect of antibiotic treatment.
When Are Antibiotics Effective?
Antibiotics may be effective in some cases of acute sinusitis, but which ones? The dilemma is that we do not have a practical clinical test for ferreting out the few patients with sinusitis-like illness who would truly benefit from antibiotic treatment. (Most patients would prefer a trial of an antibiotic to sinus puncture for definitive diagnosis.) A single randomized trial of antibiotic treatment of rhinosinusitis has shown a modest benefit of such treatment when the diagnosis was made on the basis of a positive CT scan of the sinuses16 (56% of patients treated with placebo, 82% of those treated with penicillin, and 89% of those treated with amoxicillin were substantially better on day 10 of treatment). But CT sinus scans are expensive and not readily available in outpatient practice.