title: Absorption of different oral dosage forms of oxycodone in the elderly: a cross-over clinical trial in patients undergoing cystoscopy.
abstract: OBJECTIVE
  To characterize the pharmacokinetics (PK) of oxycodone following intravenous injection and administration of three oral dosage forms (solution, capsule, and controlled-release tablet) in elderly patients (age 76-89 years) undergoing cystoscopy.
  
  
  METHODS
  This was an open, randomized study with two sequences and two visits in 15 elderly patients. The patients were given intravenous injection (over 10 min) of 5 mg of oxycodone hydrochloride trihydrate. Oxycodone hydrochloride (5 mg in all forms) was orally administered as a solution, a capsule, and a controlled-release tablet. Venous blood samples were collected up to 17 h after oxycodone administration. Population PK parameters were calculated with NONMEM VI 2.0. For intravenous injection we calculated clearance, volume of distribution at steady state, and the half-life of elimination, and for oral dosage forms also the absolute bioavailability.
  
  
  RESULTS
  Clearance of the intravenous injections was 28.9 L/h; the volume of distribution at steady state and the half-life of elimination were 186 L and 5.2 h, respectively. The absolute bioavailability of oxycodone was 59 % from oral solutions, 64 % from capsules, and 55 % from controlled-release tablets.
  
  
  CONCLUSIONS
  Our results indicate that, in the elderly, the bioavailability of the three different oral dosage forms of oxycodone is fairly similar.
authors.affiliation: Department of Anesthesia and Operative Services, Kuopio University Hospital, PO Box 1777, FI-70211, Kuopio, Finland.
authors.forename: Merja
authors.initials: M
authors.lastname: Kokki
authors.forename: Pyry
authors.initials: P
authors.lastname: Välitalo
authors.forename: Ilpo
authors.initials: I
authors.lastname: Rasanen
authors.forename: Sirpa
authors.initials: S
authors.lastname: Aaltomaa
authors.forename: Ilkka
authors.initials: I
authors.lastname: Ojanperä
authors.forename: Matti
authors.initials: M
authors.lastname: Eskelinen
authors.forename: Hannu
authors.initials: H
authors.lastname: Kokki
mesh_terms: D000042:Absorption; D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics; D001682:Biological Availability; D018592:Cross-Over Studies; D003558:Cystoscopy / Q000379:methods*; D004304:Dosage Forms; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D010098:Oxycodone / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics*
chemical_list: D000701:Analgesics, Opioid; D004304:Dosage Forms; D010098:Oxycodone