Would someone care to explain why AD's cause urinary retention, i.e.
how anti-cholinergic effects work on the body; if these side effects
are totally reversible on discontinuation of the med?

Any pharmacists there care to explain how AD's cause urinary retention;
what the anticholinergic effects are; if they are totally reversible on
drug stoppage? Thanks for your comments.

Certain anti-depressants (most notably the tricyclics) have an
"anti-cholinergic" effect.  So what does this mean?  There are
receptors in the body (muscarinic receptors) which are activated
by acetylcholine (a neurotransmitter).  Anti-depressants may block
the muscarinic receptor resulting in "anti-cholinergic" effects.
Anti-cholinergic effects include urinary retention, dry mouth,
blurry vision, etc...
Urinary retention is caused by the decrease in muscle tone of the
ureters.  Normally the muscle tone is maintained by stimulation
of the muscarinic receptors.
Side effects usually decrease as the drug is removed.  Rarely is the
condition permanent.

Thomas Kakuda

I recently switched from Prozac to Wellbutrin, and the urinary side
effects have gone away (although at least so far, I don't feel nearly as
well as I did on Prozac). It doesn't make sense to me that all of the
SSRI's I've tried have produced the same urinary side-effects......they
supposedly have little or no anti-cholinergic properties.  It's almost as
if these {*filter*} cause my prostate gland to become inflamed, because the
symptoms mimic those of chronic non-bacterial prosatitis, or of benign
prostate hyperplasia, yet they go away when I discontinue the medication.
I hope somebody can make some sense out of this, because it's been driving
me nuts for months trying to figure it out!   Thanks..

Antidepressant {*filter*} (i.e. the tricyclic antidepressants), in addition to
blocking the reuptake of norepinephrine and serotonin, can also
antagonize the effects of acetylcholine at muscarinic receptors in a
dose-related manner.

Simplified, acetylcholine released at the ends of parasympathetic nerves
(specifically the pelvic nerves) causes contraction of the detrusor and
relaxation of the trigone and sphincter of the bladder (The sphincter is
also under somatic control as well.  The spinal reflex to empty occurs at
around 400mL when there is a marked sense of fullness - the first urge
to void in contrast is felt around 150mL).

Therefore, the anticholinergic effects of preventing contraction of the
bladder smooth muscle and contracting the sphincter can lead to urinary
retention which should reverse upon discontinuation as the drug is
eliminated from the body.

..if I remember my pharmacology correctly...it has been a while.

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John Baskette

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