Pharmacokinetics of oral ketorolac in the rat

The pharmacokinetics of ketorolac, a potent analgesic agent used for relief of moderate to severe pain, has been studied in rats who received oral doses of 1, 3.2 or 5.6 mg/kg of ketorolac tromethamine. Blood samples were obtained at selected times during 24 h after medication, and ketorolac concentrations were determined by high performance liquid chromatography. After administration of ketorolac, blood concentrations increased rapidly reaching a dose-dependent maximal concentration in about 20 min. Then, concentrations decayed with a half-life of about 6 h. A linear increase in Cmax and AUC as a function of the dose was observed, and not statistically significant difference was observed in AUC/dose or Cmax/dose between doses, indicating that pharmacokinetics of ketorolac is linear in the range of doses studied.