One and two doses of cephradine in the prophylaxis of experimental streptococcal endocarditis

The efficacy of cephradine in the prophylaxis of rabbit Streptococcus sanguis endocarditis was investigated. Three days after cardiac catheterization and prior to challenge with S. sanguis, rabbits received either 1000 mg/kg (ten animals) or 500 mg/kg cephradine intramuscularly. Infective endocarditis was prevented in only 30% of the animals. The addition of a second dose of cephradine (100 mg/kg) 8 h after an initial dose of 400 mg/kg did not prevent streptococcal endocarditis in 80% of animals tested. In one or two dose regimens cephradine was found to be inferior to a single 400 mg/kg prophylactic dose of amoxycillin. Cephradine is not recommended for prophylaxis against streptococcal endocarditis.