[Pharmacovigilance study of azithromycin tablets (500 mg) in the treatment of adult patients with respiratory tract infections].

Our aim was to study a new form of azithromycin (500 mg tablets) in order to evaluate the tolerability and the influence of the ingestion of food on tolerability, the efficacy and treatment compliance in a large number of patients with respiratory tract infections. We carried out an open, non-comparative, multicenter, observational and prospective pharmacovigilance study of 3223 outpatients with respiratory tract infections randomly assigned to receive a daily dose of azithromycin for three months taken either during or outside meals. Patients were evaluated during an initial visit and two later ones in order to record the adverse events and establish the clinical efficacy. The diagnostics were as follows: pharyngotonsillitis (1200), acute otitis media (394), acute bronchitis (1134), exacerbation of chronic bronchitis (436), and community-acquired pneumonia (53). The overall therapeutic efficacy was satisfactory (cure or improvement) in 96% to 97% at the second visit and in 93% to 94% in the third (pharyngotonsillitis, 93%; acute otitis media, 91%; acute bronchitis, 94%; exacerbation of chronic bronchitis, 94%; and community-acquired pneumonia, 96%). A total of 170 adverse events were reported in 141 patients (4.4%); 12 were severe yet not related to the study medication. Eighty-eight patients showed adverse events presumed to be related to azithromycin; most were in the digestive tract. No differences in tolerability were observed in relation to food intake. Treatment compliance was high (97%). The elevated clinical efficacy, adequate compliance and the excellent tolerability profile of azithromycin tablets make them a safe and effective alternative in the treatment of respiratory tract infections.