|
March 2001 Approximately 30%-40% of acute sinusitis cases are caused by Streptococcus pneumoniae. the emergence of highly drug-resistant S. pneumoniae has placed a strong emphasis on treating this condition appropriately. Therefore, updated treatment recommendations for the management of sinusitis have been developed. The Drug-Resistant S. pneumoniae (DRSP) Therapeutic Working Group and the Sinus and Allergy Health Partnership have developed clinical treatment guidelines that can help direct clinical practice. Acute bacterial sinusitis is most often preceded by a viral upper respiratory infection (URI). Therefore, when patients present with clinical symptoms, it is often difficult to discern whether the causative agent of sinusitis is bacterial or viral. When the causative microorganism is bacterial, S. pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the most prevalent pathogens. Antibiotic-resistant strains of the bacteria that cause acute sinusitis are on the rise. Unfortunately this contributes to the increased numbers of treatment failures seen in clinical practice. In the United States, it has been estimated that approximately 33%-58% of S. pneumoniae is penicillin-nonsusceptible, while 40% of H. influenzae and 98% of M. catarrhalis are ß-lactamase producing. S. pneumoniae alters drug binding sites and efflux pumps to generate resistance to ß-lactams, fluoroquinolones, trimethoprim/sulfamethoxazole (TMP-SMX), and macrolides. Both H. influenzae and M. catarrhalis produce resistance through stimulation of ß-lactamases. The cause of antibiotic resistance is multifactorial. Overuse of antibiotics, inappropriate dosing, and the empiric selection of broad-spectrum antibiotics have all been implicated in perpetuating this problem. Judicious use of antibiotics to treat URIs (eg, sinusitis) is a primary strategy to control the prevalence in drug resistance. Recommendations for the treatment of acute sinusitis follow similar approaches to acute otitis media. Amoxicillin and amoxicillin-clavulanate (Augmentin, GlaxoSmithKline) remain the mainstays of therapy, but with higher doses of up to 3.5 g/day for patients at risk of resistant S. pneumoniae Cefpodoxime (Vantin, Pharmacia), cefuroxime (Zinacef, GlaxoSmithKline), and cefprozil (Cefzil, Bristol-Myers Squibb) remain effective treatments for acute sinusitis. However, similar to the treatment of otitis media, TMP-SMX and macrolides (azithromycin [Zithromax, Pfizer], clarithromycin [Biaxin, Abbott] and erythromycin) are less frequently recommended due to high levels of resistance. Fluoroquinolones are suggested for adult patients with moderately severe sinusitis, ß-lactam allergies and for second-line treatment of unresolved sinusitis. Antibiotic therapy for acute sinusitis should be avoided when the causative pathogen is viral. To increase the likelihood of implementing antibiotic therapy for bacterial sinusitis, the Sinus and Allergy Health Partnership emphasize that antibiotic treatment of acute sinusitis should only be initiated if symptoms have not improved after 10 to 14 days or have worsened after five to seven days. Guidelines for the treatment of acute sinusitis are summarized in table 1. Drug-resistance with S. pneumoniae H. influenzaeand M. catarrhalis must be considered when treating acute sinusitis. Rational use of antibiotics based on evidence-based guidelines is recommended to prevent further increases in resistance and enhance treatment success. Severity of illness and recent exposure to antibiotic therapy are essential considerations that help to guide the selection of therapy.
For more information: |
