title: Effect of clonidine and yohimbine on sleep in healthy men: a double-blind, randomized, controlled trial.
abstract: OBJECTIVE
  To study the acute effect of clonidine, an alpha 2-adrenoceptor agonist, and yohimbine, an alpha 2-adrenoceptor antagonist, on nocturnal sleep in healthy men.
  
  
  METHODS
  McGuire Veteran Affairs Medical Center, Richmond, Virginia, USA.
  
  
  METHODS
  Eight healthy male volunteers.
  
  
  METHODS
  Each subject slept in the sleep laboratory for 2 consecutive nights on three separate sessions, at 3-week intervals. On the 2nd night of each session, the subjects received yohimbine (5.4 mg), clonidine (0.1 mg), or placebo in a double-blind, randomized, placebo-controlled, crossover design.
  
  
  RESULTS
  There were no apparent effects of yohimbine. In contrast, clonidine completely suppressed rapid eye movement (REM) sleep in one subject and reduced REM sleep in the remaining seven subjects.
  
  
  CONCLUSIONS
  Our study confirms that clonidine markedly decreases REM, even at a low single dose, and supports the hypothesis of the important role of alpha 2-receptors in controlling REM sleep.
authors.affiliation: Medical College of Virginia, Richmond, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gentili
authors.forename: M F
authors.initials: MF
authors.lastname: Godschalk
authors.forename: D
authors.initials: D
authors.lastname: Gheorghiu
authors.forename: K
authors.initials: K
authors.lastname: Nelson
authors.forename: D A
authors.initials: DA
authors.lastname: Julius
authors.forename: T
authors.initials: T
authors.lastname: Mulligan
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000328:Adult; D003000:Clonidine / Q000494:pharmacology*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D008875:Middle Aged; D012895:Sleep, REM / Q000187:drug effects*; D015016:Yohimbine / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D015016:Yohimbine; D003000:Clonidine