The pharmacology of clavulanic acid and ticarcillin combined

The pharmacokinetics of ticarcillin and clavulanic acid were studied in normal volunteers. Ticarcillin at 50 mg/kg was combined with clavulanic acid at 1.7 and 3.4 mg/kg and infused over 30 minutes. Peak serum levels of ticarcillin were 325 micrograms/ml and its pharmacokinetic parameters were similar when combined with either dose of clavulanic acid. Peak serum levels of clavulanic acid were 8 micrograms/ml for 1.7 mg/kg and 15.8 micrograms/ml for 3.4 mg/kg. Serum concentrations of clavulanic acid were greater than or equal to 1 microgram/ml for 2 h with the 1.7 mg/kg dose and for 3 h with the 3.4 mg/kg dose. Serum half-lives of ticarcillin and clavulanic acid were similar, 1.2 hours. Urinary concentrations of ticarcillin exceeded 100 micrograms/ml and clavulanic acid concentrations exceeded 1 microgram/ml for 6 h. The serum and urine levels were such that many beta-lactamase producing organisms would be inhibited by this combination.