Once daily clarithromycin extended-release vs twice-daily amoxicillin/clavulanate in patients with acute bacterial sinusitis: a randomized, investigator-blinded study.

OBJECTIVE: To compare the efficacy and tolerability of clarithromycin extended-release (ER) to amoxicillin/ clavulanate in patients diagnosed with acute bacterial sinusitis.

RESEARCH DESIGN AND METHODS: In a controlled, multicenter, investigator-blinded study, 437 ambulatory patients at least 12 years old with signs/symptoms and radiographic findings of acute sinusitis were randomized to receive clarithromycin ER 1000 mg once daily or amoxicillin/ clavulanate 875 mg/l25 mg twice daily for 14 days.

MAIN OUTCOME MEASURES: Clinical and bacteriological response rates were determined at a test-of-cure visit, which was conducted up to 10 days following the completion of treatment. Radiological response was assessed at a follow-up visit.

RESULTS: The clinical cure rate in clinically evaluable patients was 98% (184/188) in the clarithromycin ER group and 97% (179/185) in the amoxicillin/clavulanate group (95% CI for the difference in rates [-2.4%, 4.7%]). Clinical cure was sustained at the follow-up visit (96% for each treatment group). The pathogen eradication rates were 94% (61/65) in the clarithromycin ER group and 98% (61/62) in the amoxicillin/clavulanate group (95% CI for difference in rates [-12.0%, 2.9%]). The radiological success rate was 94% (172/183) in both the clarithromycin ER and amoxicillin/clavulanate groups (95% CI for difference in rates [-4.9%, 4.9%]). Symptomatic improvement or relief was observed as early as 2 days-5 days after the initiation of study drug, with a statistically significantly higher resolution rate of sinus pressure (p = 0.027) and improvement/resolution rate of nasal congestion (p = 0.035) during treatment with clarithromycin ER. The resolution/improvement rate at the test-of-cure visit for each treatment group was > or = 94% for the primary acute sinusitis signs/symptoms, with a statistically significantly higher resolution/improvement rate of purulent nasal discharge with clarithromycin ER (p = 0.010). Both study drugs had a positive and rapid impact on quality of life. Patients reported a high level of satisfaction and probability of using either study antibiotic again, and health care resource use was low, with slightly fewer sinusitis-related physician and outpatient visits required by patients in the clarithromycin ER group (p = 0.055). The treatment groups were comparable with respect to incidence of drug-related adverse events.

CONCLUSION: In this multinational population of patients with acute bacterial sinusitis, clarithromycin ER was comparable, and for selected measures superior, to amoxicillin/clavulanate based on clinical, bacteriological, and radiological responses as well as quality of life measures, satisfaction with antibiotic therapy, and health care resource utilization.