urinary incontinence

2 etiologies of UI

1. inability to store urine: bladder contracts too often, sphincter(s) cannot contract sufficiently to allow the bladder to store urine (cannot keep it from leaking)

   result= bladder never fills to capacity and patient experiences frequent incontinent episodes of small or moderate urine volume

2. inability to empty/void urine: bladder unable to contract appropriately, outlet of sphincter is partially obstructed

   result= bladder fills beyond capacity and overflows; patient experiences abdominal distention and frequent leakage

risk factors for UI

caffeine, fluid intake, immobility, biological sex, bowel problems, smoking, parity, UTIs, menopause, GU surgery, lack of post partum pelvic floor exercise, meds

3 types of incontinence

overflow

stress

urge

what is stress incontinence

transient loss of small amounts of urine with increased intra abdominal pressure (Coughing, laughing, sneezing, bending, lifting, posterior urethrovesicular changes- parity, surgery)

due to urethral sphincter weakness

stress incontinence risk factors

pregnancy, vaginal childbirth, obesity (abdominal)

more common in women

what is urge incontinence/overactive bladder (+ causes)

abnormal bladder contractions as a result of detrusor muscle instability:

• detrusor muscle is overactive

• contracts inappropriately during filling phase

detrusor instability can be the result of:

• nerve damage- stroke, PD, MS, DM

• spinal cord damage

• unknown cause

what is overflow incontinence (+ causes)

occurs when intravesicular pressure exceeds intraurethral pressure- only at high volumes

most common type of UI seen in males with BPH

causes include:

• bladder outlet obstruction (BPH, prostate cancer)

• diabetic neuropathy, spinal cord lesions below T-11

• drugs: muscle relaxants, CCB, anticholinergics, alpha agonists

what is functional incontinence

inability of normally continent person to reach the toilet in time to avoid an accident

MSK limitations (joint pain, arthritis, muscle weakness)

unfamilar setting, lack of conventional toilet facilities

not caused by bladder or urethral specific factors

also seen in people with dementia and cognitive deficits

causes of UI without specific urogenital pathology

D- delirium/confused state

I- infection

A- atrophic urethritis/vaginitis

P- pharmaceuticals

P- psychiatric issues

E- excessive urinary output (hyperglycemia, hypercalcemia)

R- restricted mobility

S- stool impaction

iatrogenic incontinence

incontinence related to med use

drugs contributing to incontinence

alpha agonists- urinary retention

alpha blocker- urinary leakage

anticholinergics- urinary retention and/or functional incontinence

B agonists- urinary retention

B blocker- urinary leakage, urgency

CCBs- retention

diuretics- polyuria

narcotics- urinary retention and/or functional incontinence

alcohol- polyuria and/or functional incontinence

antihistamines- urinary retention and/or functional incontinence

caffeiene- polyuria

what type of UI is inability to store urine

urge or stress

what type of UI has outlet obstruction

overflow

what type of UI has inability to reach toilet

functional

urge incontinence most common urodynamics

detrusor hyperactivity

stress incontinence most common urodynamics

sphincter incompetence

overflow incontinence most common urodynamics

outlet obstruction, detrusor hypoactivity

functional incontinence most common urodynamics

normal

possible etiologies of detrusor hyperactivity

uninhibited contractions, local irritation, CNS causes

possible etiologies of sphincter incompetence

urethral hypermobility, sphincter damage

possible etiologies of outlet obstruction

physical (BPH, tumor, stricture), neurologic lesions, meds

possible etiologies of detrusor hypoactivity

neurogenic bladder (diabetes, alcoholism)

clinical features of stress incontinence

involuntary leakage of urine when coughing, laughing, sneezing, bending or lifting

patients dry over night

clinical features of urge incontinence

urgency, frequency, nocturia, frequent small volume voiding (>8 episodes per day)

no characteristic findings on physical exam, although CNS dysfunction may be apparent

clinical features of overflow incontinence

palpable or percussable bladder

suprapubic tenderness

low urinary flow rates

post void residual volume 150-200cc

functional incontinence clinical features

accident on the way to the toilet

early morning incontinence

first line therapy for stress, urge and mixed UI

non pharm

non pharm therapies

prompted voiding

bladder training- timed voiding

pelvic floor muscle exercises

biofeedback

exercise/weight loss

pessary

**remove causative meds where appropriate

what type of meds may aggravate stress incontinence

alpha blockers

specific therapies for stress incontinence

duloxetine (off label use)

vaginal estrogens (select circumstances)

what cases of SUI may benefit from vaginal estrogens

menopausal women with mixed UI + vaginal atrophy

examples of vaginal estrogens for SUI

conjugated vaginal estrogen cream (Premarin)

estradiol-17B vaginal ring (Estring)

estradiol-17B vaginal tablet (Vagifem)

ae of vaginal estrogens

vaginal discharge

local irritation/pruritis

spotting

duloxetine ae

nausea (esp initially, reduced if taken with food)

CNS- headache, insomnia, dizziness

increased BP

constipation and dry mouth

risk of suicidal idealation (transient)

may cause hepatotoxicity

drug interactions with duloxetine

substrate and inhibitor of CYP2D6 and substrate of 1A2

increased risk of serotonin syndrome when combined with other serotonergic agents

is pseudoephedrine used for SUI

last line therapy- not recommended but some use when all else fails

ineffective and can result in serious ae

specific therapies for urge incontinence

antimuscarinics/anticholinergics (Second line)

beta 3 agonist

vaginal estrogens

TCAs

botulinum toxin

prefered treatment option for urge incontinence if fail non pharm

antimuscarinics

effectiveness of antimuscarinics

only modestly effective- may only reduce urination or incontinence by 1 episode per day

increase bladder capacity/storage

decrease urgency episodes

may decrease nocturia

available antimuscarinic agents

oxybutynin, tolterodine, fesoterodine, trospium, darifenacin, solifenacin

which muscaranic receptor blockage in the detrusor muscle results in bladder relaxation

M3, M2 (more M3)

blockade of M3 receptors in other area of body besides detrusor results in what effects

dry mouth and constipation

blockade of M1 receptors in brain results in

sleepiness and cognitive impairment

what characteristics of antimuscaranics can influence unwanted CNS effects

lipophilicity, charge or polarity and molecular size

M1 selectivity

which antimuscaranic is least likely to cross BBB and cause CNS effects

darifenacin

which antimuscarinic is most likely to cross BBB and cause CNS effects

oxybutynin

which antimuscarinic is considered gold standard

oxybutynin

dosage forms of oxybutynin

IR tab, ER tab, transdermal patch

oxybutynin ae

significant anticholinergic SE: dry mouth and eyes (mucous membranes), increased IOP (vision problems), CNS= dizziness, sleepiness, cognitive impairment, urinary retention, constipation

Is ER or IR oxybutynin tolerated better

ER

benefits of oxybutynin patch form

avoids first pass metabolism

less metabolite produced= lower side effects

how long can it take to see maximum benefit with oxybutynin

may take atleast 4wks with oral, less with patch

does tolterodine or oxybutynin have more anticholinergic SEs

oxy

dosage forms of tolterodine

IR tab, SR cap

when are dosage adjustments required with tolterodine

renal and hepatic impairment, when taking with potent 3A4i

drug interactions with tolterodine

metabolized by 3A4 abd 2D6

dose decrease required when used with potent 3A4inhibitors

no dose adjustment required when used with 2D6 inhibitors

how long does max benefit take with tolterodine

up to 8wks

solifenacin selectivity

slightly more selective for M3 than M1

drug int with solifenacin

metabolized by CYP3A4

when is dosage adjustment required in solifenacin

severe renal impairment <30mL/min, when took potent 3A4i

is solifenacin, tolterodine, or oxybutynin better tolerated

solifenacin

ae of solifenacin

primarily anticholinergic- dry mouth, constipation, tachycardia

differences between fesoterodine and tolterodine

fesoterodine is a prodrug and is not converted by 2D6

when are dosage reductions required with fesoterodine

renal and hepatic dysfxn or with use of potent 3A4 inhibitors

allergy to be aware of with fesoterodine

contains soya lecithin- avoid in patients with peanut or soybean allergy

when is dosage adjustment required with tropsium

age 75+, severe renal impairment (<30mL/min)

which antimuscarinic needs to be taken on an empty stomach

trospium

which antimuscarinic is most M3 selective

darifenacin

drug int with darafenacin

metabolized by 3A4 and 2D6

when is dose decrease required in darifenacin

elderly, potent 3A4 inhibitors

darifenacin side effects

dry mouth, constipation

contraindications for darifenacin

in patients at risk of urinary retention, gastric retention, uncontrolled narrow angle glaucoma

what is mirabegron

selective beta 3 agonists

place in therapy for mirabegron

alternative to antimuscarinics, if not tolerated/contraindicated - efficacy is similar but very expensive

better tolerated than antimuscarinics and may improve adherence

ae of mirabegron

hypertension, tachycardia, nasopharyngitis, UTIs

drug int with mirabegron

mod 2D6 inhibitor

weak inhibitor of pgp - can increase digoxin and dabigatran levels

QT prolonging

therapy of choice in overflow incontinence

surgery- in many men with chronic retention due to BPH

specific therapies for overflow incontinence

alpha blockers (first line)- faster onset

• prazosin, terazosin, doxazosin, tamsulosin, alfuzosin

5 alpha reductase inhibitors (ex: finasteride, dutasteride)

non pharm functional incontinence

scheduled bathroom visits

bedside commode if needed

assist with functional disabilities

management of UI in pregnancy

preventative measures- pelvic floor muscle training

what causes UI in pregnancy

hormonal changes, weight gain

main type of UI in pregnancy

stress incontinence

who is at increased risk of UI in pregnancy

advanced maternal age and higher BMI