Effects of clonidine and yohimbine on the pupillary light reflex and carbachol-evoked sweating in healthy volunteers.
The effects of single doses of clonidine hydrochloride (200 micrograms), yohimbine hydrochloride (22 mg), a combination of the two treatments, and placebo, on some autonomic functions were studied in healthy volunteers using a double-blind crossover design. Clonidine prolonged the recovery time of the light reflex, lowered systolic blood pressure and reduced subjectively rated alertness; these effects were reversed by yohimbine. Responsiveness of sweat glands to carbachol was not affected by the treatments.
Morley
M J
MJ
Department of Psychiatry, University of Manchester.
Bradshaw
C M
CM
Szabadi
E
E
D000328:Adult; D000339:Affect / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology*; D003000:Clonidine / Q000494:pharmacology*; D004311:Double-Blind Method; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008027:Light; D008297:Male; D012025:Reflex, Pupillary / Q000187:drug effects*; D013546:Sweating / Q000187:drug effects*; D015016:Yohimbine / Q000494:pharmacology*
D015016:Yohimbine; D002217:Carbachol; D003000:Clonidine