Pharmacokinetics and ventilatory effects of oxycodone before and after liver transplantation

The pharmacokinetics and ventilatory effects of oxycodone were studied in six volunteer patients with end‐stage liver cirrhosis before and after orthotopic liver transplantation. Plasma samples and urine were collected for 24 hours after intravenous administration of 0.05 mg/kg oxycodone hydrochloride. Concentrations of oxycodone and its metabolites, noroxycodone and oxymorphone, were measured in plasma and urine. The median elimination half‐life of oxycodone was 13.9 hours (range, 4.6 to 24.4 hours) in patients with cirrhosis before transplantation and 3.4 hours (range, 2.6 to 5.1 hours) after transplantation (p < 0.05). Correspondingly, oxycodone clearance increased from 0.26 L/min (range, 0.15 to 0.73 L/min) before transplantation to 1.13 L/min (range, 0.71 to 3.98 L/min) after transplantation (p < 0.05). Oxycodone depress edventilation more strongly before transplantation than after transplantation (p < 0.05). Care should be exercised when oxycodone is used in patients with end‐stage liver disease. Clinical Pharmacology & Therapeutics (1997) 61, 655–661; doi: