The pharmacokinetics of meropenem in surgical patients with moderate or severe infections.

The pharmacokinetics of meropenem were studied in a group of 11 surgical patients (four male, seven female; mean age 63 years; mean weight 72 kg) all of whom had moderate or severe infection and who received a mean dose of 14.5 mg/kg +/- 2.7 meropenem 8-hourly iv for a minimum of 4 days. Venous blood samples were collected at timed intervals after the first dose on day 1 and the second dose on the fourth or fifth day of therapy. Serum meropenem concentrations were assayed by HPLC and fitted to a two compartment pharmacokinetic model. The mean pharmacokinetic parameters (+/- standard deviation) on day 1 were T1/2 84.6 +/- 24.1 min, Vdss 0.22 +/- 0.06 L/kg, AUC 6028 +/- 1983.2 mg.min/L, Cltot 188 +/- 67 mL/min and MRT 89.1 +/- 67.8 min. On the fourth or fifth days of therapy the values were T1/2 79.9 +/- 18.2 min, Vdss 0.17 +/- 0.8 L/kg, AUC 6000.7 +/- 2417 mg.min/L, Cltot 190 +/- 60 mL/min and MRT 67.8 +/- 30.4 min. Although the T1/2, Vdss and MRT decreased from day 1 to day 4 or 5 these changes were not statistically significant (Student's t-test, P > 0.05). Total clearance of meropenem was linearly related to creatinine clearance or patient age on the first day of therapy. Although the T1/2 and MRT were longer and the Cltot lower than those reported for young healthy volunteers, they were similar to those found in elderly volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)