Phase III, randomized, double-blind study of clarithromycin extended-release and immediate-release formulations in the treatment of adult patients with acute maxillary sinusitis.

BACKGROUND

Clarithromycin has an established bacteriologic efficacy and safety profile in the treatment of respiratory tract infections.

OBJECTIVE

This study compares the efficacy and tolerability of extended-release and immediate-release formulations of clarithromycin in patients with acute maxillary sinusitis.

METHODS

Fourteen days' treatment with once-daily clarithromycin was compared with the immediate-release, twice-daily formulation in a phase III, randomized, double-blind, parallel-group, multicenter study. Patients aged > or =12 years with signs, symptoms, and a radiologically confirmed diagnosis of acute maxillary sinusitis were eligible. Patients were assessed before treatment, within 48 hours after treatment, on study days 16 to 18, and at the test-of-cure visit on study days 24 to 31. Patients who received > or =1 dose of study drug were included in the safety analysis.

RESULTS

Of 283 patients treated, 245 were included in the efficacy analysis (122 in the extended-release group, 123 in the immediate-release group). Treatment groups were well matched with respect to demographic characteristics and medical condition and history. At the test-of-cure visit, 85% of patients in the clarithromycin extended-release group and 79% in the immediate-release group were deemed clinical cures; 89% and 91% in the extended-release and immediate-release groups, respectively, demonstrated radiographic success. Overall incidences of study drug-related adverse events were similar in the 2 treatment groups (32% in the extended-release group and 28% in the immediate-release group); however, significantly fewer patients receiving extended-release clarithromycin (2/142 11%]), compared with those receiving the immediate-release formulation (10/141 [7%]: P = 0.02) discontinued therapy because of drug-related gastrointestinal symptoms or abnormal taste. No clinically meaningful changes in laboratory values or vital signs were observed during the study.

CONCLUSION

Although the efficacy of the 2 formulations was comparable, once-daily clarithromycin extended-release was better tolerated than the twice-daily immediate-release formulation by patients with acute maxillary sinusitis.