Posted by Sunnely on November 29, 2000, at 23:54:50
In reply to Night sweats, posted by Jen111111111 on November 24, 2000, at 17:29:12
> The past week I've woken up freezing yet covered in sweat. I take 75mg Effexor and most recently Atenolol for high blood pressure. The night sweats didn't start until the Atenolol. Is this a side effect of the Effexor or something related to high blood pressure?? I'm a bit concerned. Any advice is welcome.
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Hi Jen1111,
The cause(s) of night sweats may differ from sweating in general and has different possible diagnostic considerations including infection, tumor, and endocrine disorder, in addition to antidepressant side effects. Granted your night sweats is not due to any other medical condition, most probably venlafaxine (Effexor) is the main culprit. SSRIs (Prozac, Zoloft, Paxil, Luvox, Celexa) and Effexor have been reported to cause sweating in 7%-11% and 12% of patients, respectively. The package insert (PI) for Effexor indicates an increased the incidence (rate of occurrence) of sweating with increased dose.
The exact mechanism as to how Effexor induced sweating is unclear, but presumably involves increased norepinephrine, stimulating both the preganglionic sympathetic cholinergic fibers innervating (supplying) the sweat glands and the subpopulation of beta-adrenergic receptors on the glands themselves. Sweating may also be a direct effect of the drug (e.g., antidepressant) on the hypothalamus.
It was suggested that benztropine (Cogentin), an anticholinergic drug, may provide relief in cases of Effexor-induced sweating. It is believed that benztropine blocks the acetylcholine receptors on the eccrine sweat glands and thereby causing a reduction in sweating. A more detailed explanation of this effect is proposed as follows: The eccrine sweat glands are stimulated by the sympathetic nervous system; however, the postganglionic fibers that reach the muscarinic receptors on the end organ are cholinergic. The preoptic and anterior nuclei are the specific areas of the hypothalamus that contain heat sensitive and cold sensitive nerve cells and are mainly responsible for the stimulation of these sweat glands. At least two cases of Effexor-induced sweating alleviated by benztropine have been reported in the literature.
On a side note, approximately 80% of menopausal women experience sweating, along with the usual "hot flashes."
References:
1) Pierre JM, Guze BH: Benztropine for venlafaxine-induced sweats (letter to editor). Journal of Clinical Psychopharmacology 2000(April);20:269.
2) Garber A, Gregory RJ: Benztropine in the treatment of venlafaxine-induced sweating (letter to editor). Journal of Clinical Psychiatry 1997;58:176-177.
poster:Sunnely
thread:49357
URL: http://www.dr-bob.org/babble/20001115/msgs/49664.html