Postmarketing surveillance for clarithromycin in patients with community-acquired pneumonia

We conducted postmarketing surveillance for clarithromycin (CAM), a macrolide antimicrobial, and assessed its efficacy and safety in adult patients with community-acquired pneumonia. We considered 262 patients registered in the surveillance for validation of "Guidelines for Management of Community-Acquired Pneumonia in Adults (revised 2005)" during July 2006-March 2007 from 97 participating institutions across Japan. CAM was selected according to the basic early treatment flowchart in the guidelines. Safety and efficacy analyses were respectively performed for 219 and 153 patients. The mean age of patients for efficacy analysis was 45.3 years; the severity of community-acquired pneumonia was assessed using the severity scoring system in the guidelines (A-DROP scoring system), and the disease severity in patients was categorized as mild, 117 patients (76.5%); moderate, 32 patients (20.9%); and severe, 4 patients (2.6%). On the basis of the pneumonia type, patients were categorized as having suspected atypical pneumonia, 109 patients; suspected bacterial pneumonia, 39 patients; and pneumococcal pneumonia, 5 patients. Further, patients were treated in accordance with the guidelines, and the treatment regimen included CAM monotherapy or CAM combined with other antimicrobials as per the attending physician's judgment, in which the average dose was for 10.0 days. The response rate was 96.3% (105/109) in patients with suspected atypical pneumonia and 84.6% (33/39) in patients with suspected bacterial pneumonia Among the 109 patients with suspected atypical pneumonia, only CAM was administered for 82 patients and CAM in combination with other antimicrobials was administered for 27 patients, with response rates of 97.6% and 92.6%, respectively. In 39 patients with suspected bacterial pneumonia, only CAM was administered for 14 patients and CAM in combination with other antimicrobials was administered for 25 patients, with response rates of 71.4% and 92.0%, respectively. In 5 patients with pneumococcal pneumonia, CAM was administered in combination with other antimicrobials, and the treatment was shown to be effective in all patients. During safety analysis, adverse reactions were observed in 7 of 219 patients in the safety analysis group; thus, the incidence of adverse reactions was 3.2%. The major adverse reaction observed was laboratory abnormalities in 4 patients; no other serious events were observed.