Dose-response relationship for oral idazoxan effects in healthy human subjects: comparison with oral yohimbine.
The effects of oral administration of the alpha 2 adrenergic receptor antagonists idazoxan (20 mg, 40 mg, 80 mg) and yohimbine (20 mg) were compared using a placebo-controlled within-subjects design. Healthy subjects completed 5 test days during which medication effects on mood and anxiety states, physiologic indices, plasma cortisol levels, and plasma levels of the norepinephrine metabolite 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) were assessed. Idazoxan dose-dependently increased plasma MHPG, plasma cortisol, systolic and diastolic blood pressure, and Panic Attack Symptom Scale scores in healthy subjects. Overall, yohimbine and idazoxan produced a similar pattern of behavioral and neuroendocrine responses. Since idazoxan possesses relatively greater receptor specificity compared to yohimbine, it may be a more useful alpha 2 antagonist in humans.
Krystal
J H
JH
VA-Yale Alcoholism Research Center, West Haven, CT 06516.
McDougle
C J
CJ
Woods
S W
SW
Price
L H
LH
Heninger
G R
GR
Charney
D S
DS
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000328:Adult; D000339:Affect / Q000187:drug effects; D001519:Behavior / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D004146:Dioxanes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D019329:Idazoxan; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000097:blood; D009490:Neurosecretory Systems / Q000187:drug effects*; D016584:Panic Disorder / Q000139:chemically induced / Q000523:psychology; D011674:Pulse / Q000187:drug effects; D015016:Yohimbine / Q000494:pharmacology*
D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D015016:Yohimbine; D008734:Methoxyhydroxyphenylglycol; D006854:Hydrocortisone; D019329:Idazoxan