Cefetamet (hydrochloride)

Cefetamet (Ro 15-8074) hydrochloride is a cephalosporin antibiotic and the active metabolite of Cefetamet pivoxil (HY-B1894A). Cefetamet hydrochloride binds to bacterial penicillin-binding protein (PBP) (IC₅₀ for PBP3 in Escherichia coli W3110 is 2.5 μg/mL). Cefetamet hydrochloride has significant activity against Gram-negative bacteria such as Enterobacteriaceae, Neisseria species, and Haemophilus influenzae, as well as Gram-positive bacteria such as Streptococcus. Cefetamet hydrochloride kills and lyses Treponema pallidum. Cefetamet hydrochloride can be used in the research of respiratory tract, urinary tract, ear, nose and throat infections, and syphilis^{[1][2][3][4][5]}. IC50 & Target:IC₅₀: 2.5 μg/mL (PBP3 in Escherichia coli W3110^[3] In Vitro:Cefetamet hydrochloride exhibits high in vitro activity against most members of the Enterobacteriaceae, Haemophilus influenzae, Neisseria spp., and Streptococcus pneumoniae (MIC₉₀ ≤ 2 μg/mL)^[2].
Cefetamet hydrochloride shows high in vitro activity against Enterobacteriaceae, Neisseria spp., Vibrio spp., Haemophilus influenzae and streptococci other than enterococci^[3].
Cefetamet hydrochloride exhibits poor affinity for the PBPs of Staphylococcus aureus, with IC₅₀s of 90, >100, 52 and >100 μg/mL for PBP 1 to 4^[3].
Cefetamet (0.05-0.1 μg/mL; 24 h) hydrochloride kills and lyses Treponema pallidum in vitro^[4].
In Vivo:Cefetamet (1-30 mg/kg; i.m.; once) hydrochloride cures experimental syphilis in rabbits, with the best effect when administered before clinical manifestations^[4].