Pharmacokinetics and tissue penetration of Timentin: a simultaneous study of serum, urine, lymph, suction blister and subcutaneous thread fluid.

Abstract

Following iv bolus injection of 3.2 g Timentin (ticarcillin 3.0 g plus clavulanic acid 0.2 g) to 12 volunteers, the antibiotic concentrations were analysed by HPLC methods in serum, urine and fluids from subcutaneous threads, suction blisters and lymph during 8 h. Pharmacokinetic parameters, urine recovery, penetration and ticarcillin/clavulanic acid ratios were calculated. The antibiotic concentration in thread fluid closely followed the serum concentration. For ticarcillin the mean (+/- S.D.) elimination half-lives in serum and thread fluid were 1.0 +/- 0.1 and 1.2 +/- 0.1 h, respectively. For clavulanic acid the half-lives in these fluids were 0.9 +/- 0.1 and 1.0 +/- 0.1 h. The lymph and blister fluid concentration followed a similar pattern, but differed from those in serum, the mean (+/- S.D.) elimination half-lives for both compounds ranging from 1.1 +/- 0.2 to 3.2 +/- 0.3 h. The urine recovery of ticarcillin was 86% and of clavulanic acid 51% of the administered dose. The penetration of clavulanic acid into the different tissue fluids was superior to ticarcillin, ranging from 78 to 88% for clavulanic acid and 52-70% for ticarcillin. The concentration ratios of the two compounds, being 15:1 at the time of injection, varied widely in the different tissue fluids with time. This was also the case with AUC(0-infinity) ratios. A relative decrease of clavulanic acid was observed, most pronounced in serum and thread fluid. However, the antibiotic concentrations achieved in serum, urine and extravascular fluid should be adequate in most infections caused by a wide range of clinically important pathogens.