Comparison of three-day and five-day courses of azithromycin in the treatment of atypical pneumonia

Abstract

This open, randomised clinical study, conducted from June 1988 to December 1989, included 84 patients with clinical and radiological findings of atypical pneumonia. All patients were treated with a total dose of 1.5 g azithromycin, a new azalide antibiotic. In Group I, azithromycin was administered for three days (500 mg once daily). In Group II, azithromycin was administered for five days (250 mg b.i.d. on day 1, followed by 250 mg once daily on days 2 to 5). Causative pathogens were identified by serological methods. Of the 41 patients in Group I, Mycoplasma pneumoniae, Chlamydia psittaci and Coxiella burnetti were identified in 19, 4 and 3 patients, respectively. In Group II there were 43 patients; Mycoplasma pneumoniae was identified in 24, Chlamydia psittaci in 4 and Coxiella burnetti in 3. Only patients with known causative pathogens were included in the evaluation of clinical efficacy. All patients were clinically cured by day 5; most of the patients became afebrile within 48 h of starting treatment. Side effects were observed in one patient in Group I and in one patient in Group II. The results suggest that a 1.5 g total dose of azithromycin is equally effective when administered as a three- or five-day regimen for the treatment of atypical pneumonia.

In vitro activity of azithromycin (CP-62,993) against Chlamydia trachomatis and Chlamydia pneumoniae

“…Azithromycin also appears to be clinically effective in the treatment of atypical pneumonia caused by Chlamydia spp. (13). However, there are no data on its microbiological efficacy in vivo.…”

Mycoplasma pneumoniaeand Its Role as a Human Pathogen

“…The extremely high potency of azithromycin against M. pneumoniae and its long half-life probably account for its ability to cure M. pneumoniae infections with very short treatment courses, and possibly even with a single 1.5-g dose, despite the relatively slow growth of the organism (367,368). Overall, azithromycin and the investigational ketolide cethromycin (ABT-773) are the most potent drugs against M. pneumoniae in terms of MICs (436).…”

Antimicrobial susceptibility and therapy of infections caused by Chlamydia pneumoniae

“…This situation appears to be analogous in many ways to that for genital infection with C. trachomatis; no one would even consider evaluating antimicrobial efficacy by serology. However, the only treatment studies of pneumonia caused by C. pneumoniae that have been published in journals so far have relied entirely on diagnosis by serology (1,37).…”