title: Population pharmacokinetics and analgesic potency of oxycodone.
abstract: This prospective study aimed to characterize the population pharmacokinetics of intravenous oxycodone and to determine the minimum effective concentration (MEC) and minimum effective analgesic concentration (MEAC) of oxycodone for major open intra-abdominal surgery.
  
  
  
  In the pharmacokinetic study, patients were administered intravenous oxycodone (0.1 mg kg-1), and arterial blood was sampled at pre-set intervals. In the analgesic-potency study, patients were administered intravenous oxycodone (0.1 mg kg-1) 30 min before the end of the surgery, were placed in the postoperative anaesthesia care unit (PACU), and were asked to rate their pain every 10 min using a visual analogue scale (0 = no pain, 10 = most severe pain). On the first occasion that wound pain at rest and during compression was rated as ≥3 or ≥5, respectively, the first blood sample was obtained to determine the MEC. A second blood sample was obtained after titration with 2 mg of oxycodone to yield wound pain <3 at rest and <5 during wound compression, and MEAC was determined. MEC and MEAC were determined again in each patient.
  
  
  
  In the population pharmacokinetic study (n = 54), oxycodone plasma concentration over time was well described by a three-compartment mammillary model. Lean body mass and age were significant covariates for the volume of distribution and metabolic clearance of the pharmacokinetic model of oxycodone, respectively. The analgesic-potency study (n = 50) showed that the median (95% CI) MEC and MEAC were 31.5 (19.2-42.8) and 74.1 (29.2-128.3) ng ml-1(first measurements) and 63.4 (15.6-120.1) and 76.1 (32.9-132.7) ng ml-1(second measurements), respectively.
  
  
  
  In major intra-abdominal open surgery, the MEAC and analgesic potency of oxycodone were 75 ng ml-1and 60 ng ml-1, respectively.
authors: Department of Anesthesiology and Pain Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors: Byung-Moon
authors: BM
authors: Choi
authors: Department of Anesthesiology and Pain Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors: Yong-Hun
authors: YH
authors: Lee
authors: Department of Anesthesiology and Pain Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors: Sang-Mee
authors: SM
authors: An
authors: Division of Drug Safety Evaluation New Drug Development Center, Osong Medical Innovation Foundation, Chungju-si, Chungbuk, Republic of Korea.
authors: Soo-Han
authors: SH
authors: Lee
authors: Department of Statistics, Ewha Women's University, Seoul, Republic of Korea.
authors: Eun-Kyung
authors: EK
authors: Lee
authors: Department of Anesthesiology and Pain Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Republic of Korea.|Department of Clinical Pharmacology and Therapeutics, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors: Gyu-Jeong
authors: GJ
authors: Noh
mesh_terms: D000005:Abdomen / Q000601:surgery; D061605:Administration, Intravenous; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010098:Oxycodone / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D011446:Prospective Studies
chemical_list: D000701:Analgesics, Opioid; D010098:Oxycodone
keywords: analgesia; model; oxycodone; pharmacokinetic; potency