In vitro and in vivo Antibacterial Activity and Pharmacokinetics of SC-002 and Its Derivative, SC-004: New Oral Cephalosporins

Abstract

SC-002 is a novel oral cephalosporin possessing a unique thiadiazolylethenyl moiety at the 3 position. In the present study, it was the most active against gram-positive bacteria among oral cephalosporins such as cefdinir (CFDN), cefpodoxime, cefditoren and cefaclor (CCL). It was equal to or 16 times more active than CFDN against standard and clinical strains. In particular, against clinical isolates of Morganella morganii and Haemophilus influenzae, SC-002 was 8–64 times more active than CFDN. The antibacterial activity of SC-002 against some β-lactam-resistant strains was superior to that of CFDN. The in vivo antibacterial activity of SC-004, a pivaloyloxymethyl ester of SC-002, was 1.2–8 times more protective against systemic infections due to Streptococcus pneumoniae, Escherichia coli and Klebsiella pneumoniae than that of CFDN. The therapeutic effects of SC-004 on experimental respiratory tract infections caused by S. pneumoniae or H. influenzae were superior to those of CFDN and CCL. SC-004 showed higher and longer-lasting blood levels and higher urinary excretion in pharmacokinetics in mice.

Cefditoren, a New Aminothiazolyl Cephalosporin

“…Other studies have established the in vitro activity of cefditoren. 8,[19][20][21][22][23][24][25][26][27][28][29] Cefditoren exhibits a high degree of efficacy and tolerability when used to treat commonly encountered bacterial respiratory tract infections. Of particular interest is evidence that cefditoren has activity against ␤lactam-resistant and macrolide-resistant nonpneumococcal streptococci.…”

“…Compliance with the assigned regimen was assessed at visit 2 by pill count and was defined as consumption of 80% of tablets. The researchers excluded 175 patients from the study due to culture-negative S. pyogenes (106), noncompliance with therapy (27), consumption of other antibiotics (17), or unavailable data at visit 2 or 3 (25).…”