Effect of telithromycin and azithromycin on nasopharyngeal bacterial flora in patients with acute maxillary sinusitis.

OBJECTIVE

To explore the efficacy of the ketolide telithromycin compared with azithromycin in eradicating S pneumoniae from the nasopharynx of adults with acute maxillary sinusitis. The growing resistance of Streptococcus pneumoniae to penicillin and macrolides brought about the development of a new class of antibiotics-the ketolides-that are effective against resistant pneumococci.

SETTING

Otolaryngology clinic.

PATIENTS: One-hundred five patients with acute maxillary sinusitis.

INTERVENTIONS: Nasopharyngeal cultures were obtained before therapy and 10 to 12 days after initiation of treatment. Fifty-nine patients were treated with 500 mg of azithromycin daily for 3 days and 46 were treated with 800 mg of telithromycin daily for 5 days.

RESULTS

Sixty-seven potential pathogens were recovered prior to initiation of therapy in 57 patients, 32 treated with telithromycin and 25 treated with azithromycin: S pneumoniae (31 isolates), Haemophilus influenzae (non-type b) (13), Staphylococcus aureus (8), Streptococcus pyogenes (8), and Moraxella catarrhalis (7). The distribution of the pathogens was similar in both groups. The number of S pneumoniae isolates in the azithromycin group was reduced following treatment from 14 to 8 (43% reduction), and 5 of these 8 isolates were resistant to azithromycin. In contrast, the number of S pneumoniae isolates in the telithromycin group was reduced following treatment from 17 to 1 (94% reduction) (P < .01). This isolate was susceptible to azithromycin and telithromycin. No differences were noted in the eradication rate of all of the other potential pathogens, which were all susceptible to both azithromycin and telithromycin. Development of resistance to the antimicrobial agents used (defined as increase in the minimal inhibitory concentration by at least 2 tubes) was found only in 5 isolates (4 S pneumoniae and 1 H influenzae) recovered only from patients who received azithromycin (P < .05).

CONCLUSION

These data illustrate the superiority of telithromycin to azithromycin in the eradication of S pneumoniae from the nasopharynx.