The effect of probenecid on serum amoxycillin concentrations up to 18 hours after a single 3 g oral dose of amoxycillin: possible implications for preventing endocarditis.

Serum concentrations of amoxycillin were significantly higher with probenecid than without probenecid for up to 18 h after administration of a single 3 g oral dose of amoxycillin. At 12 to 16 h after this dose the mean serum amoxycillin concentrations exceeded the expected minimum bactericidal concentrations of amoxycillin for viridans streptococci when probenecid was given together with amoxycillin. The concurrent oral administration of probenecid with amoxycillin is discussed for the prophylaxis of endocarditis in susceptible patients who require dental procedures under general anaesthesia.