In-vitro activity of cefprozil (BMY 28100) and loracarbef (LY 163892) against pathogens obtained from middle ear fluid

• Published in: Journal of antimicrobial chemotherapy 1991-03, Vol.27 (3), p.311-318
• Main Authors: Arguedas, Adriano G., Arrieta, Antonio C., Stutman, Harris R., Akaniro, Joseph C., Marks, Melvin I.
• Format: Article
• Language: English
• Subjects: Acute Disease; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Branhamella catarrhalis; Cefprozil; Cephalosporins - pharmacology; Ear, Middle - microbiology; Haemophilus influenzae; Haemophilus influenzae - drug effects; Medical sciences; Moraxella catarrhalis - drug effects; Otitis Media - microbiology; Pharmacology. Drug treatments; Streptococcus pneumoniae; Streptococcus pneumoniae - drug effects
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/27.3.311

We compared the in-vitro activities of cefprozil, a novel oral cephalosporin, and of loracarbef, a new oral carbacephem, with other agents against middle ear fluid isolates obtained from children with acute otitis media. These included Streptococcus pneumoniae, Haemophilus influenzae and Branhamella catarrhalis. Cefprozil activity (MIC50 and MIC90) against S. pneumoniae was 0.25 and 0.50 mg/l; against H. influenzae 8 and 16 mg/l; against B. catarrhalis 2 and 2 mg/l. Loracarbef activity (MIC50 and MIC90) against S. pneumoniae was 1 and 2 mg/l; against H. influenzae 8 and 16 mg/l; against B. catarrhalis 1 and 8 mg/l. Cefprozil was four-fold more active against S. pneumoniae than loracarbef but similar to amoxycillin, amoxycillin/clavulanate, cefaclor, cefixime, cefuroxime and trimethoprim/sulfamethoxazole (TMP/SMX). Against H. influenzae, cefprozil was similar to loracarbef and other agents although less active than TMP/SMX and cefixime. Against B. catarrhalis, cefprozil was four-fold more active than loracarbef, cefaclor and cefixime but similar to the comparative antibiotics. Cefprozil and loracarbef activities were unaffected at pH 6 and 8 or in the presence of human serum, but there was a major diminution of activity for both agents at pH 5 and at inoculum sizes ≥ 107 cfu/ml. Cefprozil and loracarbef have consistent activity against middle ear pathogens and further pharmacokinetic and clinical studies appear warranted.