title: Pharmacokinetics after a single intravenous dose of the opioid ketobemidone in neonates.
abstract: BACKGROUND
  Ketobemidone is often used as an alternative to morphine in children in the Scandinavian countries. In an earlier study, we have examined the pharmacokinetic properties in children in different age groups but have not focused on neonates. The aim of this clinical trial was to explore the pharmacokinetics of ketobemidone in neonates.
  
  
  METHODS
  Fifteen full-term neonates (eight females) from 37 gestational weeks at birth and scheduled for elective surgery were included in the trial. Their median age was 3 days (range 1-18 days). Ketobemidone hydrochloride was administered as a single intravenous bolus dose, and ketobemidone concentrations were measured by liquid chromatography-mass spectrometry over 10 h. Pharmacokinetic parameters were calculated with standard compartmental methods.
  
  
  RESULTS
  The median (range) values for ketobemidone clearance, apparent volume of distribution, volume of central compartment, distribution half-life and elimination half-life were 0.46 (0.23-0.84) l/h/kg, 4.64 (3.50-7.31) l/kg, 1.71 (0.16-3.47) l/kg, 2.85 (1.04-10.78) min and 7.26 (3.5-11.3) h.
  
  
  CONCLUSIONS
  Compared with our previous study in children older than 1 year of age, the elimination of ketobemidone appeared to be slower in full-term neonates. Despite a low pharmacokinetic variability of ketobemidone as observed in the present neonatal patient population, we recommend individualizing the dose of ketobemidone based on observations of analgesic efficacy.
authors: Department of Pediatric Anesthesia and Intensive Care, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden. stefan.lundeberg@karolinska.se
authors: S
authors: S
authors: Lundeberg
authors: N
authors: N
authors: Stephanson
authors: C-O
authors: CO
authors: Stiller
authors: S
authors: S
authors: Eksborg
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000768:Anesthesia, General; D000776:Anesthesiology; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006207:Half-Life; D006801:Humans; D007231:Infant, Newborn; D007275:Injections, Intravenous; D008297:Male; D013058:Mass Spectrometry; D008614:Meperidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D000701:Analgesics, Opioid; D008614:Meperidine; C012394:ketobemidone