Overactive Bladder

Question 1

Definition of an overactive bladder (OAB)?

Answer 1

A chronic condition defined as urgency, with or without urge incontinence, usually with frequency or nocturia

Question 2

What is the most common cause of overactive bladder?

Answer 2

Detrusor overactivity (DO)

Question 3

How is DO diagnosed?

Answer 3

Urodynamic testing

Question 4

Aetiology (causes) of OAB?

Answer 4

1. Idiopathic in most cases
2. Secondary to pelvic or incontinence surgery
3. Rarely, neuropathic DO is found in the presence of conditions such as MS, spina bifida and upper motor neurone lesions
4. OAB due to outflow obstruction is uncommon in women

Question 5

Sx of OAB?

Answer 5

1. Urinary frequency
2. Urgency
3. Urge incontinence
4. Nocturia

Question 6

What do provocative factors do? Give some examples?

Answer 6

Provocative factors trigger it. Some include;

1. Cold weather
2. Opening the front door
3. Hearing running water
4. Increased intra-abdominal pressure (e.g. coughing) can trigger bladder overactivity (but note this is different from USI, which can be misleading)

Question 7

What Ix should be done?

Answer 7

1. Urine culture
2. Frequency / volume chart
3. Urodynamics

Question 8

Why is a urine culture done?

Answer 8

Exclusion of infection is mandatory, as Sx overlap with those of UTI

Question 9

What will be seen on a frequency / urgency chart?

Answer 9

Increased diurnal frequency associated with urgency and episodes of urge incontinence
Nocturia a common Fx

Question 10

What will be seen on urodynamics?

Answer 10

Involuntary detrusor contractions during the filling phase of the micturition cycle, which may be spontaneous or provoked

Question 11

What other causes of OAB must be excluded for DO to be diagnosed?

Answer 11

1. Metabolic abnormalities (e.g. diabetes or hypercalcaemia)
2. Physical causes (e.g. prolapse or foecal impaction)
3. Urinary pathology (e.g. UTI or interstitial cystitis)

Question 12

About how many women are affected by OAB?

Answer 12

1 in 6

Question 13

Does OAB incidence increase with age?

Answer 13

Yes

Question 14

What is the 1st line Tx of OAB?

Answer 14

Behaviour Mx;

1. Consume only 1-1.5L per day
2. Avoid caffeine based drinks and alcohol
3. Review drugs for diuretics and antipsychotics which can affect bladder function

Question 15

Conservative Tx options?

Answer 15

1. Behaviour therapy
2. Bladder training
3. Hypnotherapy and acupuncture

Question 16

What is done in bladder retraining?

Answer 16

Suppress urinary urge and increase intervals between voiding.
Reported cure rates are between 44-90%

Question 17

2 main medical Tx for OAB?

Answer 17

1. Anticholinergics (1st line medical Tx)

2. Oestrogens

Question 18

How do anticholinergics drugs work?

Answer 18

Block the parasympathetic nerves, thereby relaxing the detrusor muscle

Question 19

Side effects of anticholinergics?

Answer 19

Can’t see, can’t pee, can’t spit, can’t shit;

1. Dry mouth (up to 30%)
2. Constipation, nausea, dyspepsia and flatulence
3. Blurred vision, dizziness and insomnia
4. Palpitation and arrhythmias

Question 20

Contraindications to anticholinergics?

Answer 20

1. Acute (narrow angle) glaucoma
2. Myasthenia gravis
3. Urinary retention or outflow obstruction
4. Severe ulcerative colitis
5. GI obstruction

Question 21

How do oestrogens work?

Answer 21

Intravaginal oestrogens help to reduce vaginal atrophy in post-menopausal women.

Question 22

Further Tx for OAB?

Answer 22

1. Botulinium toxin A
2. Neuromodulation and sacral nerve stimulation
3. Surgery

Question 23

Name some anticholinergics and their doses

Answer 23

1. Oxybutinin (oral, 2.5-5mg, 1-4 times per day)
2. Propiverine (oral, 15mg, 2-4 times/day)
3. Solifenacin (oral, 5-10mg, daily)
4. Tolterodine (oral, 2mg bd or 4mg od)
5. Trospium (oral, 20mg bd)
6. Fesoterodine (oral, 4 or 8mg od)