You must be logged in to vote!
ugalaxy
α1 stimulation (via α1 agonist) constricts the bladder sphincter thereby, preventing sudden bouts of micturition during coughing/sneezing (abdominal stress).
+10
sammyj98
I thought that B3 stimulation stopped urination
+9
adong
@sammyj98 B3 would facilitate bladder relaxation
+
hvancampen
@sammyj98- were you thinking of oxybutynin? (thats what I thought of!) According to FA, its used for urge incontinence not stress.
+2
drzed
Nah he/she's talking about Beta-3 receptors which are Gs coupled. Gs increases cAMP thus it would cause smooth muscle relaxation -> bladder relaxation!
+1
donttrustmyanswers
From Mayo: "There are no approved medications to specifically treat stress incontinence in the United States. The antidepressant duloxetine (Cymbalta) is used for the treatment of stress incontinence in Europe, however."
+1
nreid4
@hvancampen oxybutynin is an M3 muscarinic antagonist, not B3.
+
alienfever
I thought about B3 agonist as well and got this wrong.
I think maybe B3 agonist can be used for bladder (URGENCY incontinence) where the main issue is detrusor over reactivity. In STRESS incontinence however the problem has nothing to do with detrusor, so we use α1 agonist to constrict the sphincter.
+2
fatboyslim
(FA 2020 242) Mirabegron is a B3 agonist. B3 stimulation causes detrusor muscle relaxation, hence it is used for URGE incontinence, not STRESS incontinence. I think the drug they are referring to is Ephedrine?
Also, remember "O"xybutynin (muscarinic antagonist) is for "O"veractive bladder (urge incontinence)
+1
handsome
what is the educational objective of this question?
what is the author trying to ask and want us to learn/know?
+
bcher
@handsome I would add another line to the table on FA2020 p237: alpha agonists; +alpha-1 receptor which causes bladder sphincter muscle contraction; treats stress urinary incontinence with sphincteric incontinence
+
l0ud_minority
I thought that females didn't have the internal urethral sphincter only external thus a more appropriate drug for stress urinary incontinence would be something that affects the nicotinic receptors????? Am I missing something??? If this was a male then yes alpha 1 receptors are located on the internal urethral sphincter and stimulation of them would help with symptoms in question.
+
You must be logged in to vote!
You must be logged in to vote!
You must be logged in to vote!
blue4415
wow ！ exactly what I think ～ nice metaphor
+
You must be logged in to vote!
submitted by ∗sugaplum(487)
phenylpropanolamine is an alpha agonist that stimulates urethral smooth muscle contraction. - from uptodate, however, it also says it is not recommended treatment anymore