Efficacy, safety and tolerability of azithromycin versus roxithromycin in the treatment of acute lower respiratory tract infections.

In an open, multicentre study, the clinical and bacteriological efficacy, safety and tolerance of azithromycin and roxithromycin were compared in a total of 204 adults with acute lower respiratory tract infections (LRTIs) [acute bronchitis, acute infectious exacerbations of chronic bronchitis (AIECBs), or pneumonia]. Following treatment with 500 mg/day azithromycin administered orally once daily for 3 days, a satisfactory clinical response of cure or improvement was recorded in 91/99 (91.9%) evaluable patients at the post-therapy evaluation (day 10-14). Of the 94 evaluable patients treated with roxithromycin (150 mg given orally twice daily for 10 days), 82 (87.2%) were classified as cured or improved at post-therapy. The main pathogens isolated before treatment were Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus species, Haemophilus influenzae and Moraxella catarrhalis. In the 46 azithromycin-treated patients evaluated both clinically and bacteriologically, 92.0% of pathogens were eradicated; H. influenzae persisted in one azithromycin-treated patient with acute bronchitis who was classed as clinically improved. In the roxithromycin group, 81.1% of the pathogens were eradicated in 35 patients; S. aureus persisted in one clinically cured patient with acute bronchitis, and H. influenzae persisted in one patient with AIECB and one with pneumonia, and Haemophilus species in one with AIECB, who were all classified as clinically improved. Azithromycin was well tolerated with a lower incidence of adverse events than that recorded in the roxithromycin treatment group. Treatment was not discontinued due to adverse events in any of the azithromycin-treated patients, whereas two roxithromycin-treated patients were withdrawn from treatment due to vomiting and/or dyspepsia.