RESUMO
BACKGROUND: Telithromycin is a new antibacterial agent of the ketolide class designed to provide optimal treatment against common bacterial respiratory tract pathogens. Telithromycin was derived by structural modification of the basic macrolide molecule to allow tight binding to the bacterial ribosome that enhances potency and minimizes the risk for the development of resistant strains. OBJECTIVE: The aim of this study was to compare the efficacy and tolerability of telithromycin 800 mg once daily with those of high-dose clarithromycin (500 mg twice daily), each for 10 days, in the treatment of adult patients with community-acquired pneumonia (CAP). METHODS: This randomized, double-blind, double-dummy, parallel-group clinical trial was conducted at 54 centers in the United States, Canada, Argentina, and Chile. Patients aged >or=18 years with acute CAP were randomized to receive 10-day treatment with oral telithromycin 800 mg once daily (administered as two 400-mg encapsulated tablets in the morning) and placebo (administered as 2 encapsulated tablets identical to the telithromycin in the evening) or high-dose clarithromycin (500 mg administered as two 250-mg identical encapsulated tablets twice daily). The primary outcome measure was clinical outcome at the posttherapy, test-of-cure visit (days 17-24 after the completion of therapy) in the clinically assessable per-protocol population. Secondary efficacy variables included bacteriologic outcome at the posttherapy, test-of-cure visit, and clinical and bacteriologic outcomes at the late posttherapy visit (day 31-45). Tolerability was assessed using investigator observation, patient self-reporting, clinical laboratory data, a 12-lead electrocardiogram, and physical examination (including vital signs). RESULTS: A total of 493 patients were enrolled and 448 patients received >or=1 dose of study medication (224 patients/group). A diagnosis of CAP was confirmed in 416 patients (205 men, 211 women; median age, 43 years; telithromycin, n = 204; clarithromycin, n = 212). Clinical cure rates were 88.3% (143/162) in the telithromycin group and 88.5% ( 138/56) in the clarithromycin group. Bacterial eradication rates were comparable between treatment groups (telithromycin, (28/32) [87.5%]; clarithromycin, (29/30) [96.7%]. Both treatment were fairly well tolerated; adverse events were experienced in 57.0% of the patients treated with telithromycin and 49.1% of those treated with clarithromycin; most of these were assessed as mild. CONCLUSIONS: In this study of adult patients with CAP, telithromycin 800 mg once daily was an effective and fairly well-tolerated regimen for initial empiric treatment, with clinical and bacteriologic efficacy and tolerability equivalent to therapy with high-dose clarithromycin (500 mg twice daily).