Pharmacokinetic profile of idazoxan in the beagle dog.
The alpha 2-antagonist idazoxan (2- (2- (1,4-benzodioxanyl))-2-imidazoline) has been given intravenously and orally to five beagle dogs at 1, 3 and 10 mg kg-1 doses. Idazoxan plasma levels were determined by a HPLC method. After intravenous administration, a linear kinetic behaviour was obtained. Half-life and mean residence time values ranged 105.2-117.1 and 138.1-154.0 min, respectively. Total plasma clearance values and volume of distribution at steady state values ranged from 25.6-32.1 (mL kg-1) min-1 and 3.60-4.36 L kg-1, respectively. After oral administration, time to peak values averaged around 1 h. Dose normalized peak concentration values ranged 161-182 ng mL-1. Bioavailability values ranged 60-88%. Low idazoxan bioavailability has been described in other animal species and attributed to a first-pass effect.
Vallès
J
J
Research Department, S.A. LASA Laboratorios, Barcelona, Spain.
Pruñonosa
J
J
Menargues
A
A
Nomen
M
M
Obach
R
R
D000284:Administration, Oral; D000317:Adrenergic alpha-Antagonists / Q000493:pharmacokinetics*; D000818:Animals; D004146:Dioxanes / Q000493:pharmacokinetics*; D004147:Dioxins / Q000493:pharmacokinetics*; D004285:Dogs; D006207:Half-Life; D019329:Idazoxan; D007202:Indicators and Reagents; D007275:Injections, Intravenous; D008297:Male
D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D004147:Dioxins; D007202:Indicators and Reagents; D019329:Idazoxan