title: Morphine Synovial Fluid Concentrations After Intravenous Regional Limb Perfusion in Standing Horses.
abstract: OBJECTIVE
  To determine synovial concentrations of morphine after intravenous regional limb perfusion (IVRLP) with morphine or morphine in combination with gentamicin in clinically healthy, standing sedated horses.
  
  
  METHODS
  Experimental.
  
  
  METHODS
  Adult horses (n = 6).
  
  
  METHODS
  IVRLP was performed using 0.1 mg/kg morphine (M) in standing sedated horses. After a 3-week washout period, IVRLP was performed on the same forelimb with a combination of 0.1 mg/kg morphine and 1 g gentamicin (M/G). Synovial fluid from the middle carpal joint of the perfused limb and jugular blood samples were collected immediately before each perfusion and 20 minutes, and 2, 8, and 24 hours after IVRLP. Morphine and gentamicin concentrations were determined by ELISA. Data were assessed using 2-way repeated measures ANOVA with significance set at P ≤ .05.
  
  
  RESULTS
  Synovial fluid morphine concentrations were greatest 20 minutes after perfusion. Mean ± SD peak synovial morphine concentrations over 12 perfusions were 3903 ± 4881 ng/mL. There was no significant difference in morphine synovial concentrations after M or M/G. Plasma morphine concentrations peaked within 2 hours of perfusion (range, 11-63 ng/mL). Mean peak gentamicin concentrations in synovial fluid were 76,315 ± 39,809 ng/mL. IVRLP morphine did not cause clinically apparent adverse effects.
  
  
  CONCLUSIONS
  IVRLP in standing sedated horses results in measurable levels of morphine in synovial fluid and synovial concentrations of gentamicin after perfusion in combination with morphine are equivalent to those previously reported.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Barbara G
authors.initials: BG
authors.lastname: Hunter
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Jill E
authors.initials: JE
authors.lastname: Parker
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Rita
authors.initials: R
authors.lastname: Wehrman
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Stang
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Cebra
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004338:Drug Combinations; D004797:Enzyme-Linked Immunosorbent Assay; D005552:Forelimb / Q000098:blood supply / Q000378:metabolism; D005839:Gentamicins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006736:Horses; D007262:Infusions, Intravenous; D009020:Morphine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013582:Synovial Fluid / Q000378:metabolism*; D013997:Time Factors
chemical_list: D004338:Drug Combinations; D005839:Gentamicins; D009020:Morphine