In Vivo Antibacterial Activities of Sanfetrinem Cilexetil, a New Oral Tricyclic Antibiotic

The in vivo antibacterial activities of a new oral trinem, sanfetrinem cilexetil (a prodrug of sanfetrinem), were evaluated in comparison with those of cefdinir and amoxicillin. Sanfetrinem cilexetil showed potent efficacy against experimental murine septicemia caused by Staphylococcus aureus, Streptococcus pyogenes, and Escherichia coli and against murine respiratory infections caused by Streptococcus pneumoniae. Likewise, in murine models of respiratory infection by penicillin-susceptible and penicillin-resistant S. pneumoniae, sanfetrinem cilexetil was more effective than amoxicillin in reducing the number of bacteria in infected lungs. These results were reflected in its potent in vitro activity and high levels in plasma.