Community-acquired Bacterial Respiratory Tract Infections: Consensus Recommendations

Antibacterial treatment is not recommended for patients whose clinical history and symptoms suggest a viral infection (group 0) unless symptoms persist for more than 10 to 14 days. In those cases, bacterial superinfection with M pneumoniae, C pneumoniae, or Bordetella pertussis is possible. Patients with chronic bronchitis but without risk factors for treatment failure (group 1) may be treated with a variety of first-line agents, including azithromycin, clarithromycin, cefuroxime, cefprozil, cefixime, amoxicillin, doxycycline, or trimethoprim/sulfamethoxazole. For patients in group 1 who fail first-line therapy, and as first-line therapy for patients in group 2, a fluoroquinolone or amoxicillin/clavulanate is recommended. Patients in group 3 are more likely to be infected with a Gram-negative pathogen, such as Ps aeruginosa or Enterobacter species, and are least able to tolerate treatment failure. Hence, ciprofloxacin is appropriate in the outpatient setting.

TABLE 2

Initial empiric therapy in outpatients with acute bacterial exacerbations of chronic bronchitis

Bacterial rhinosinusitis

The recommendations for management of acute bacterial rhinosinusitis issued by the Sinus and Allergy Health Partnership (SAHP), a not-for-profit organization created by the American Academy of Otolaryngic Allergy, the American Academy of Otolaryngology-Head and Neck Surgery, and the American Rhinologic Society, are based on a variety of factors. These include rate of spontaneous resolution, pathogen distribution, antibacterial resistance data, the importance of S pneumoniae in intracranial and extrasinus complications, and the ability of a patient to tolerate treatment failure (TABLE 3).¹⁷ The panel reviewed more than 150 published articles on management of children and adults with bacterial rhinosinusitis.

As in the pneumonia guidelines, recent antibiotic use is an important consideration when selecting an antibiotic since resistant pathogens are likely. β-Lactam agents play a major role as initial therapy in both children and adults. This recommendation is consistent with those of Williams et al who reviewed 49 clinical trials involving 13,660 patients. These investigators recommended 7 to 14 days of penicillin or amoxicillin for acute maxillary sinusitis confirmed radiographically or by aspiration.³⁸

The SAHP recommended higher doses of amoxicillin (with or without clavulanate) in patients who have recently taken an antibiotic or who have moderate disease. Fluoroquinolones are recommended as alternatives in patients with mild disease who have not taken an antibiotic in the last 4 to 6 weeks. However, in patients with mild disease who have taken antibiotics recently or who have moderate disease, fluoroquinolones are recommended as first-line therapy. Macrolides are recommended only for patients with a β-lactam allergy since failure rates of 20% to 25% are possible. Lack of improvement or worsening symptoms after 72 hours should prompt reevaluation, may necessitate cultures and/or a CT scan, and should raise the possibility of causal organisms other than S pneumoniae, H influenzae, and M catarrhalis.

TABLE 3

Initial empiric therapy in outpatients with acute bacterial rhinosinusitis

Dose and duration

While each of the three guidelines provides detailed recommendations regarding selection of an antibacterial agent, the dose and duration of therapy generally are not well defined. Fortunately, other sources provide guidance in these 2 areas.