Laboratory and clinical studies on ritipenem acoxil

We performed laboratory and clinical studies on ritipenem acoxil (RIPM- AC), a new oral penem antibiotic, with the following results. 1. Antimicrobial activity. Minimal inhibitory concentrations (MIC) of ritipenem (RIPM) were measured for 223 clinical isolates of 11 species, and its antimicrobial activity was compared with ampicillin (ABPC), cefaclor (CCL), cephalexin (CEX) and cefpodoxime (CPDX). The MIC values of RIPM against gram positive cocci were equal to those of ABPC, and superior to those of CCL, CEX and CPDX. In contrast, those of RIPM against gram-negative bacteria were superior to those of ABPC, CCL and CEX, but inferior to those of CPDX. 2. Clinical efficacy. The clinical efficacy of RIPM-AC was evaluated in 12 patients : 6 with pneumonia, 1 with bronchopneumonia, 3 with bronchitis, 1 with bronchiectasis and 1 with lung abscess. The patients were given a daily dose of 450~600 mg for 7~28 days. The clinical response was excellent in 2 cases, good in 8, fair in 1, and poor in 1, the efficacy rate being 83.3%. Bacterial strains were eradicated in 1 case, decreased in 4 and unchanged in 1 by treatment with RIPM-AC. As adverse reactions, dyspepsia and eosinophilia and elevation of GPT were observed in one case each.