title: The pharmacokinetics of inhaled morphine delivered by an ultrasonic nebulizer in ventilated dogs.
abstract: BACKGROUND
  To investigate the pharmacokinetics of single dose morphine inhaled by modified ultrasonic nebulizer versus intravenous administered in ventilated dogs.
  
  
  METHODS
  Six healthy dogs were randomly assigned to receive nebulized or intravenous morphine and crossed over to the alternative medication 1 week after. Morphine was nebulized by modified ultrasonic nebulizer (YuYue 402A, Jiangsu, China). Arterial blood was sampled every minute during the 10 min of administration and at 2, 5, 7, 10, 15, 20, 45, 60, 90, 120, 150, 180, 240, and 360 min after the administration for the determination of morphine concentration by RP-HPLC.
  
  
  RESULTS
  The main pharmacokinetic parameters of morphine by inhaled and intravenous administration were: MRT 59±14 min versus 19±4 min, T(1/2) 21.9±5.1 min versus 3.3±1.0 min, T(max) 23.0±2.7 min versus 8.8±2.4 min, C(max) 0.245±0.09 mg·L⁻¹ versus 1.09±0.32 mg·L⁻¹, AUC(0-∞) 9.7±1.1 mg·min·L⁻¹ versus 15.2±7.2 mg·min·L⁻¹, CL 0.069±0.019 L·min⁻¹·kg⁻¹ versus 0.063±0.028 L·min⁻¹·kg⁻¹, and the absolute bioavailability of inhaled morphine was 35.5±10%. There were no significant differences (p<0.05) between inhaled and intravenous morphine in AUC and CL. As expected, the T(½) and MRT of inhaled morphine were significantly greater than those of intravenous morphine.
  
  
  CONCLUSIONS
  Morphine nebulized by ultrasonic nebulizer can be rapidly and extensively absorbed by lungs in ventilated dogs.
authors: Anesthesiology Department, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, People's Republic of China.
authors: Xin
authors: X
authors: Xu
authors: Xiaohai
authors: X
authors: Wang
authors: Weihong
authors: W
authors: Ge
authors: Lin
authors: L
authors: Pan
authors: Man
authors: M
authors: Zheng
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D005260:Female; D008297:Male; D009020:Morphine / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D009330:Nebulizers and Vaporizers; D014465:Ultrasonics
chemical_list: D009020:Morphine