Pharmacokinetics of ketorolac in children after abdominal surgery.

The pharmacokinetics of 2 doses of intravenous ketorolac (0.5 and 0.9 mg x kg-1) were studied in 14 children (age 2-8 years). A single dose of the drug was injected into the dorsum vein of one hand. Blood samples were collected at regular time intervals for 6 hours. Serum ketorolac concentrations were assayed using a high pressure liquid chromatography method. Pharmacokinetic values were estimated by a nonlinear computer program. The distribution volume (Vdarea), the total clearance (Cltotal), and elimination half-life (t1/2 beta) were similar in both groups of children who either received 0.5 or 0.9 mg x kg-1 of ketorolac. The estimated geometric mean Vdarea, Cltotal, and t1/2 beta ratios (95% CI in parentheses) for 0.9 mg x kg-1:0.5 mg x kg-1 were 1.24 (0.82, 1.50), 1.14 (0.88, 1.23), and 1.083 (0.40, 1.81), respectively. The pharmacokinetic parameters found in this study are different from those found by other authors in adult subjects.