Comparative pharmacokinetic study between lenampicillin, bacampicillin and amoxycillin.

A cross-over study was performed comparing serum kinetics and urinary excretion in six healthy, fasting volunteers after ingestion of comparable amounts of lenampicillin, bacampicillin and amoxycillin. Venous blood samples and urine samples were taken at intervals for 6 and 12 h respectively post-tablet ingestion and assayed for free ampicillin or amoxycillin concentration with Bacillus subtilis as indicator organism. The most rapid Tmax and the highest Cmax were achieved with lenampicillin. The AUC was similar for lenampicillin, bacampicillin and amoxycillin as was the total percentage urinary recovery of antibiotic. Potential pharmacokinetic advantage of orally administered lenampicillin and bacampicillin compared to comparable doses of amoxycillin are higher peak serum concentrations (12.0 mg/l lenampicillin; 9.7 mg/l bacampicillin; 7.6 mg/l amoxycillin) and more rapid time to peak concentration (0.6 h lenampicillin; 0.7 h bacampicillin and 1.4 h amoxycillin).