Clonidine raises the sweating threshold in symptomatic but not in asymptomatic postmenopausal women.
OBJECTIVE
To determine the effects of clonidine, which reduces central sympathetic activation, on the sweating threshold in postmenopausal women with and without hot flashes.


METHODS
Laboratory physiologic study.


METHODS
University medical center.


METHODS
12 healthy postmenopausal women reporting frequent hot flashes and 7 reporting none.


METHODS
In two separate sessions, participants received a blind intravenous injection of clonidine HCl (2 microg/kg of body weight) or placebo, followed by body heating.


METHODS
Core body temperature, mean skin temperature, sweat rate, sternal skin conductance level, and blood pressure.


RESULTS
Symptomatic women had significantly lower core body temperature sweating thresholds than asymptomatic women after receiving placebo. Clonidine significantly increased this threshold in symptomatic women but lowered it in asymptomatic women.


CONCLUSIONS
These results support the hypothesis that elevated brain norepinephrine levels reduce the sweating threshold in symptomatic women, thereby contributing to the initiation of menopausal hot flashes.
Freedman
R R
RR
Wayne State University School of Medicine, Detroit, Michigan, USA. aa2613@wayne.edu
Dinsay
R
R
D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects; D003000:Clonidine / Q000627:therapeutic use*; D005260:Female; D005712:Galvanic Skin Response / Q000187:drug effects; D019584:Hot Flashes / Q000188:drug therapy*; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D012881:Skin Temperature / Q000187:drug effects; D013546:Sweating / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D003000:Clonidine