Comparison of ceforanide, cefazolin, methicillin, and nafcillin in Staphylococcus aureus endocarditis therapy in rabbits.

Ceforanide (30 mg/kg) administered every 12 h, cefazolin (20 mg/kg) administered every 8 h and methicillin or nafcillin (40 mg/kg) administered every 6 h were equally effective in reducing the number of Staphylococcus aureus in vegetations in rabbits with endocarditis. These treatments were more effective than methicillin or nafcillin administered every 12 h. Ceforanide produced higher peak concentrations and greater bactericidal activity in serum than the other drugs and had the longest half-life (5.8 h, compared with 0.4 to 0.8 h for the other agents.