CLINICAL EFFICACY OF DIRITHROMYCIN IN PATIENTS WITH BACTEREMIC PNEUMONIA

Dirithromycin is a new macrolide antimicrobial drug with a long half-l ife (44 hours) that reaches high tissue concentrations, thus permittin g once-daily oral dosing and shorter courses of therapy. Soon after ab sorption, dirithromycin enters the tissue so rapidly that serum concen trations are comparatively low. It could be hypothesized that these lo w serum levels could endanger the outcome in patients with bacteremic pneumonia. We reviewed the database on dirithromycin pneumonia (consis ting of 1108 patients randomized to receive dirithromycin or erythromy cin in two double-masked trials) to ascertain its efficacy in patients with community acquired pneumonia and concomitant bacteremia. Fourtee n (2.5%) of 555 dirithromycin-treated patients and 10 (1.8%) of 553 er ythromycin-treated patients had bacteremia. A favorable clinical respo nse posttherapy was observed in 92.3% and 88.9% of these patients with a response assigned, respectively. Overall, favorable response rates were comparable between the two groups in the bacteremic subsets: pati ents with pneumococcal bacteremia, patients with nonbacteremic pneumoc occal pneumonia, and all patients enrolled with acute pneumonia who ha d a posttherapy clinical response. In the treatment of patients with m ild or moderate community-acquired pneumonia, including those with uns uspected and incidental bacteremia, dirithromycin is an effective macr olide antimicrobial drug.