Urinary incontinence

Question 1

What controls the bladder emptying?

• division
• nerve
• receptors

Answer 1

Parasympathetic s2-s4
Pelvic nerves
M2 and 3 receptors

Question 2

What controls the bladder filling?

• division
• nerve
• receptors

Answer 2

Sympathetic T11-L2
Hypogastric nerve
Beta 3 receptors

Question 3

What controls urethra closure? (external sphincter)

• division
• nerve
• receptors

Answer 3

S2-S4
Pudendal nerve (somatic) located at Onuf’s nucleaus
Also at the male bladder neck: alpha1A adrenergic

Question 4

What controls external sphincter opening?

• division
• nerve
• receptors

Answer 4

NOS/NO

Question 5

What are the sensory bladder afferents?

Answer 5

30% A delta fibres (sense of fullness via spinobulbospinal pathway via pontine micturition centre)

70% unmyelinated C fibres (usually silent but activated by irritation like infection and after SCI drive the spinal segmental reflex pathway)

Question 6

What parts of the brain have control of voiding?

Answer 6

Superomedial frontal lobes- overall inhibition
Pontine micturition centre and storage centre- near locus coeruleus
Descending spinal tracts inhibit and facilitate voiding
Spinal cord centre (S2-4 Onuf’s nucleus-somatic- and parasympathetic neurons)

Question 7

How does oxybutynin work in incontinence?

Answer 7

anticholinergic&raquo_space; direct smooth muscle relaxant
High affinity for M3 more than M2 and M1 receptors
IR tablet most commonly used. Can get a patch which has reduced metabolite N-desethyl oxybutynin–> reduction in dry mouth ++. Skin rash in quite a few

Darifenacin has fewer CNS side effects
Fewer neurocog side effects if IR oxybutynin

Question 8

Side effects oxybutynin, solifenacin etc

Answer 8

Dry mouth
Lethargy
Constipation
Confusion
Potential for tachycardia
Can precipitate open angle glaucoma

Question 9

How much does antichoniergic drug reduce urge and incontinence on average.

Answer 9

0. 5 ep per day urge

0. 7 ep per day less incontinence

Question 10

What is the mechanism of tamsulosin?

Answer 10

Alpha blocker for BPH and overactive bladder

Question 11

How does dutasteride work?

Answer 11

5 aplha reductaase inhibitor to reduce prostate size in BPH

Question 12

How does Mirabegron work and when is it used?

Answer 12

Beta3 agonist–>bladder relaxation

Fewer side effects than cholinergics: not dry mouth, minimal effects on pulse and BP