PP203—Whole Blood Cannabinoid Pharmacokinetic Parameters in Heavy and Occasional Smokers. Do Oral Fluid Cannabinoid Measurements Correlate with Whole Blood data in Heavy Smokers?

Abstract

2013 e81 cancer patients. The aim of this study was evaluate the plasma concentrations of oxycodone and its demethylates and opioid-induced adverse effects based on cachexia stage in cancer patients receiving oxycodone. Patients (or Materials) and Methods: Seventy patients receiving oxycodone for cancer pain at Hamamatsu University Hospital were enrolled. Cachexia was evaluated using the Glasgow Prognostic Score (GPS). Predose plasma concentrations of oxycodone, oxymorphone, and noroxycodone were determined at the titration dose. Opioidinduced adverse effects were monitored for 2 weeks after the titration. Results: Fourteen patients had a GPS of 0, 27 a GPS of 1, and 29 a GPS of 2. Plasma concentrations of oxycodone and oxymorphone but not noroxycodone in patients with a GPS of 2 were significantly higher than that with a GPS of 0. The metabolic ratios of noroxycodone but not oxymorphone to oxycodone in patients with a GPS of 1 and 2 were significantly lower than in those with a GPS of 0. A higher GPS was associated with a higher incidence of somnolence, while the GPS did not affect the incidence of vomiting. Plasma concentrations of oxycodone and oxymorphone were not associated with the incidence of adverse effects. Conclusion: Cancer cachexia raised the plasma exposures of oxycodone and oxymorphone through the reduction of CYP3A but not CYP2D6. Although the cachexia elevated the incidence of somnolence, alterations in their pharmacokinetics were not associated with the incidence. Disclosure of Interest: None declared.