A randomized comparative study on the safety and efficacy of clarithromycin and erythromycin in treating community-acquired pneumonia.

Clarithromycin, a new macrolide, has distinct microbiological and pharmacokinetic advantages compared with erythromycin. This study was designed to compare the safety and efficacy of clarithromycin and erythromycin in the treatment of community-acquired pneumonia.Forty adult patients, diagnosed with community-acquired pneumonia, were randomly arranged to received either clarithromycin 250 mg twice daily (20 patients) or erythromycin 500 mg four times daily (20 patients), over a period of 14 days each.There were no statistically significant differences between the two groups in terms of clinical cure (65% for clarithromycin, 65% for erythromycin), clinical success (clinical cure and improvement: 95% for clarithromycin, 90% for erythromycin) and radiological response (95% for clarithromycin, 90% for erythromycin). However, adverse effects, mainly gastrointestinal, were significantly higher among patients treated with erythromycin than among patients treated with clarithromycion (p < 0.05).These results demonstrate that clarithromycin 250 mg twice daily is at least as effective as erythromycin 500 mg four times daily for the treatment of community-acquired pneumonia, and is much better tolerated.