This study was designed to evaluate the efficacy of a 3 day course of
azithromycin in low to moderately severe community-acquired
pneumonia. Forty patients with low to moderately severe community-acquired
pneumonia (29 males, 11 females, mean age 46 +/- 17 yrs; 20 pretreated with betalactams for 2-10 days with no results before admission to hospital; 18 with evidence of co-morbidity) were enrolled in an open, randomized study with
azithromycin, 500 mg q.d. oral
therapy for 3 days, versus
clarithromycin, 250 mg b.i.d. oral
therapy for 10 +/- 2 days. The aetiology of
pneumonia was identified in 18 patients by serology (nine Mycoplasma pneumoniae, four Chlamydia pneumoniae, five Legionella pneumophila; one patient with chlamydial
infection also had Klebsiella pneumoniae bacteraemia). A presumptive aetiological diagnosis was obtained with sputum culture in three other patients (one Haemophilus influenzae, two Haemophilus parainfluenzae), all strains were sole isolates with 10(8) Colony forming units (CFU), and with Gram
stain in one patient with Streptococcus pneumoniae. All patients in the
azithromycin group (one after a second 3 day course), and all but two (of those available for evaluation) of the
clarithromycin group were cured. Defervescence occurred after 2.6 +/- 1.6 days, and chest roentgenogram cleared after 8.9 +/- 3.3 days, with no difference between the two groups. Tolerance was good, and there were no withdrawals from
therapy.(ABSTRACT TRUNCATED AT 250 WORDS)