COMPARISON OF AZITHROMYCIN VERSUS CLARITHROMYCIN IN THE TREATMENT OF PATIENTS WITH UPPER RESPIRATORY-TRACT INFECTIONS

The efficacy and safety of azithromycin and clarithromycin were compared in an open multicentre study involving 380 adult patients with acute otitis media, acute sinusitis, or acute streptococcal pharyngitis or tonsillitis. Patients were assigned randomly to receive azithromycin as a single dose of 500 mg daily for three days, or darithromycin 250 mg bid for ten days. Overall clinical efficacy was found to be similar in each treatment group at day 10–14, with a satisfactory outcome (cured or improved) in 95% of azithromycin and 96% of darithromycin patients. Bacteriological efficacy was also similar, with eradication of the pathogen in 94% and 95% of isolates, respectively, in the azithromycin and clarithromydn groups. In otitis media, a satisfactory clinical response was seen in 97% of patients in each treatment group. Azithromycin therapy resulted in a clinical response rate of 93% in sinusitis patients, with bacteriological eradication in 93% of patients. Two patients (who were cured clinically) had persistent pathogens. Similarly, darithromycin achieved clinical response and bacteriological eradication in 95% and 92% of sinusitis patients, respectively. Pathogens persisted in two patients with clinical cure, and in one case of clinical failure. In pharyngitis or tonsillitis, Streptococcus pyogenes was eradicated successfully in 95% of patients in both groups, and the clinical success rates were 96% and 97% for azithromycin and darithromycin, respectively. No case of clinical failure was associated with persistence of S. pyogenes infection. At the follow-up assessment of this diagnosis group, reinfection had occurred in three (8%) azithromycin patients and one (3%) darithromycin patient, and all but one patient remained asymptomatic. Both drugs were well-tolerated, with 8.4% of patients on azithromycin and 7.4% on darithromyrin reporting adverse events, mainly gastrointestinal. It was concluded that a three-day course of zithromycin was as effective and well-tolerated as a ten-day course of darithromycin in adults with acute upper respiratory tract infections. © 1993, The British Society for Antimicrobial Chemotherapy.