Urinary Incontinence and Retention

Question 1

What ANS tone of bladder controls what?

Answer 1

SNS: filling
PNS: emptying:

Question 2

What regions control SNS and PNS in bladder?

Answer 2

Spinal reflex loops
Pontine
High brain control

Question 3

What stops the bladder from contracting? Clamps the outlet shut?

Answer 3

Spinal reflex loop from hypogastric nerve to:

B3 (NorEpi) receptors: Stops PNS contraction
A1 (NorEpi) receptors: clamps internal urethra

Question 4

B3 stimulation by norepinephrine from hypogastric nerve does what?

Answer 4

Stops PNS contraction of bladder

Question 5

A1 stimulation by norepinephrine from hypogastric nerve does what?

Answer 5

Clamps shut internal urethral sphincter

Question 6

What is the voluntary control of the bladder mediated by?

Answer 6

Pontine storage center:

Pudendal nerve to external urethral sphincter by Nicotinic M receptors (Ach)

Question 7

What does stimulation of nicotinic M receptors by pudendal nerve lead to?

Answer 7

Ext. erethral sphincter closing

Question 8

How does the PNS cause micturation?

Answer 8

Inhibiting the PNS

Question 9

What is voluntary emptying of the bladder controlled by?

Answer 9

Periaqueductal grey matter:

Centrally inhibits pontine storage center to stop pudendal nerve closing of ext. urethral sph.

Inhibits hypogastric B3 stimulation and PNS inhibition, overides A1 stimulation leading to int. urethral sph. closure

Stimulates pelvic nerve to detrussor to M3 receptors (Ach) leading to contraction of bladder and relaxation of internal sphincter

Question 10

Summary of voluntary control receptors?

Answer 10

Up: M3 (Ach) in detrussor via pelvic

Down: B3 (NE) in bladder via hypogastric
A1 (NE) in internal urethra via hypogastric
M (Ach) in external urethra via pudendal

Question 11

What are the most commonly used drugs for overactive bladder?

Answer 11

Antimuscarinics: block Ach action on M3 in detrussorrr

Tolterodine
Oxybutynin

Question 12

What is used for overactive bladder?

Answer 12

Anticholinesterase: boost Ach effect

Neostigmine

Question 13

What are the most common AEs of urinary retention drugs?

Answer 13

Block Ach: “dry as a bone, mad as a hatter, red as a beet, blind as a bat”
dry mouth: worse in elderly
constipation
tachycardia

Question 14

What are contraindications of antimuscarinics?

Answer 14

Glaucoma
UG/GI obstruction
Alzheimers (worsens the disease)

Question 15

What are the rankings of antimuscarinics, in terms of side effects?

Answer 15

Solifenacin>Tolterodine>Oxybutyinin

Question 16

What is concerning about antimuscarinics with drug discontinuation?

Answer 16

Withdrawal

Question 17

What are the durations of antimuscarinics?

Answer 17

Solifenacin: 60 hrs
Trospium: 20
Darifenacin: 15 (M3 selective(
Oxybutyinin: 2/13 with ER

Question 18

What is a M3 selective antimuscarinic?

Answer 18

Darifenacin

Question 19

What is special about solifenacin, compared to other antimuscarinics?

Answer 19

Long half life
CYP
Highest oral availability
Low renal excretion

Question 20

What is the only antimuscarinic with no CYPs?

Answer 20

Trospium has NO CYPs
Poor oral bioavailbility: take on empty stomach
80% renal excretion

Question 21

What is notable about Trospium metabolism?

Answer 21

NO CYPS (only one in class!)
Poor oral availability: need empty stomach
80% renal excretion

Question 22

What is a B3 specific sympathomimetic that prevents PNS from emptying bladder?

Answer 22

Mirabegron

Question 23

What is notable about the metabolism of miragebron?

Answer 23

Low oral

CYP interaction with butrylcholinersterase, UGT, EtOH dehydrogenase

Question 24

What are AEs of sympathomimetics?

Answer 24

BP
HTN
Tachycardia

Question 25

What drug is used for urinary retention?

Answer 25

Neostimine

Question 26

What are AEs of neostigmine?

Answer 26

Opposite SLUDGEBBB:
Mad as hatter
Red as beet
Dry as bone
Blind as bat
Hot as hare?

Question 27

What are the effects of opiates on bladder?

Answer 27

Retention:
mu and delta receptors in sacral cord inhibit PNS
reverse with opiate antagonists