Efficacy and safety of intravenous sulbactam/ampicillin 3 g 4 times daily in Japanese adults with moderate to severe community-acquired pneumonia: a multicenter, open-label, uncontrolled study.

Although sulbactam/ampicillin (SBT/ABPC) 3 g 4 times daily (QID) is widely used worldwide for patients with moderate to severe community-acquired pneumonia (CAP), the 3 g QID regimen was not available in Japan. In fact, there has been no evidence from a formal clinical study regarding the efficacy and safety of SBT/ABPC 3 g QID in these patients. We report the first results of a multicenter, unblinded, non-comparative, phase 3 study of SBT/ABPC 3 g QID in Japanese adults with moderate to severe CAP. Forty-seven subjects with moderate to severe CAP were enrolled and received SBT/ABPC 3 g QID intravenously for 3-14 days. The clinical responses assessed by the data review committee (DRC) were the primary endpoints. The secondary endpoints included the bacteriological responses assessed by the DRC. The clinical efficacy rate at the test of cure (TOC) was 94.6%. The bacterial eradication rate at TOC was 91.7%. Causative pathogens were isolated from sputum sample taken at baseline in 28 subjects (59.6%). Common causative pathogens included Streptococcus pneumoniae (14 strains), Haemophilus influenzae (9 strains), and Moraxella catarrhalis (8 strains). The clinical efficacy rate and the bacterial eradication rate at TOC of the common pathogens were, respectively, 92.3% and 90.0% in subjects with S. pneumoniae, 83.3% and 75.0% in subjects with H. influenzae, and 87.5% and 87.5% in subjects with M. catarrhalis. All treatment-related adverse events were mild or moderate in severity. SBT/ABPC 3 g QID was well tolerated and demonstrated excellent clinical and bacteriological responses. ClinicalTrials.gov Identifier: NCT01189487.