2. Overactive Bladder
• veractive bladder (OAB) is a clinical condition characterized by
urinary urgency with or without incontinence, urinary
frequency and nocturia.
• feel like we need to pass urine many times during the day and
night, and may also experience unintentional loss of urine
(urgency incontinence).
• OAB affects approximately 17% of the population in USA
3. Feel a sudden urge to urinate that's difficult
to control
Experience unintentional loss of urine immediately
after an urgent need to urinate (urgency incontinence
Wake up more than two times in the night to urinate (nocturia)
Symptoms of OAB
Urinate frequently, usually eight or more times in
24 hours
4. • The kidneys produce urine, which drains into your bladder.
When we urinate, urine passes from your bladder through a
tube called the urethra.
• A muscle in the urethra called the sphincter opens to release
urine out of the body
• In women, the urethral opening is located just above the
vaginalopening.
• In men, the urethral opening is at the tip of the penis.
5. Urinary bladder
• The urinary bladder can store up to 500 ml of urine in women and
700 ml in men.
• feel the need to urinate (pee) when bladder has between 200 and
350 ml of urine in it.
• While emptying empty bladder, the muscle bladder wall tightens
to squeeze the urine out of bladder, while at the same time the
sphincter muscles at the base of bladder relax, allowing the urine
to flow out through urethra.
6. • In men, the urethra leads through the penis and is about 20 cm
long. In women, it ends above the opening of the vagina.
• The urethra is shorter in women (only 3 to 5 cm long), so it’s
easier for germs from the anus to enter their bladder.
• This is one of the reasons why urinary tract infections (UTIs)
like cystitis are more common in women.
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7. • As our bladder fills, nerve signals sent to our brain
eventually trigger the need to urinate.
• When we urinate, these nerve signals coordinate the
relaxation of the pelvic floor muscles and the muscles
of the urethra (urinary sphincter muscles).
• The muscles of the bladder tighten (contract),
pushing the urine out.
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8. • Overactive bladder happens when the muscles of the
bladder start to contract on their own even when the
volume of urine in our bladder is low.
• These are called involuntary contractions, and they
create an urgent need to urinate.
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9. Several conditions may contribute to signs and
symptoms of overactive bladder, including:
Neurological disorders, such as stroke and multiple sclerosis
Diabetes
UTI that can cause symptoms similar to those of an OAB
Hormonal changes during menopause in women
Conditions affecting the bladder, such as tumors or bladder stones
Factors that get in the way of urine leaving the bladder, such as enlarged
prostate, constipation or previous surgery to treat incontinence
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10. OAB symptoms may also be associated with:
Medications that cause our body to make a lot of urine or require that we take them
with lots of fluids
Drinking too much caffeine or alcohol
Declining cognitive function due to aging, which may make it more difficult for your
bladder to understand the signals it receives from our brain
Difficulty walking, which can lead to bladder urgency if we are unable to get to the
bathroom quickly
Incomplete bladder emptying, which may lead to symptoms of overactive bladder, as
we have little urine storage space left
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11. Risk factors
• As we age, we at increased risk of developing overactive
bladder. We are also at higher risk of diseases and disorders,
such as enlarged prostate and diabetes, which can contribute to
other problems with bladder function.
• Many people with cognitive decline — for instance, those who
have had a stroke or have Alzheimer's disease — develop an
overactive bladder.
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12. Complications
• Any type of incontinence can affect our overall quality of life. If
OAB symptoms cause disruption to our life, we might also have:
• Emotional distress or depression
• Anxiety
• Sleep disturbances and interrupted sleep cycles
• Issues with sexuality
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13. Tests of bladder function
• Urodynamic tests include:
• This test is important if there's concern about ability to empty bladder
completely when we urinate. Remaining urine in the bladder (post-void
residual urine) may cause symptoms identical to those of an overactive
bladder.
• To measure residual urine after we have voided, your doctor may request
an ultrasound scan of your bladder. The ultrasound scan translates sound
waves into an image, showing how much urine is left in your bladder after
you urinate. In some cases, a thin tube (catheter) is passed through the
urethra and into your bladder to drain the remaining urine, which can then
be measured.
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14. Measuring urine flow rate
To measure the volume and speed of our
voiding, we may be asked to urinate into a
device (uroflowmeter).
A uroflowmeter catches and measures the
urine, and translates the data into a graph of
changes in our flow rate.
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15. Measuring urine left in the bladder.
• The ultrasound scan translates sound waves
into an image, showing how much urine is left
in our bladder after we urinate. In some cases,
a thin tube (catheter) is passed through the
urethra and into your bladder to drain the
remaining urine, which can then be measured.
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16. Testing bladder pressures.
• Cystometry is a test that measures pressure in our bladder and in the
surrounding region as our bladder fills.
• During this test, our doctor uses a thin tube (catheter) to fill our bladder
slowly with warm fluid.
• Another catheter with a pressure-measuring sensor is placed in the rectum
or, for women, inthe vagina.
• The sensor tells how much pressure our bladder has to exert to empty
completely.
• This procedure can identify whether we have involuntary muscle
contractions or a stiff bladder that's not able to store urine under low
pressure.
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18. OAB
• OAB occurs as a result of abnormal and involuntary
contractions of the detrusor muscle in the bladder,
caused by muscarinic receptors (M2 and M3
subtypes).
• Stimulation of M2 and M3 receptors by acetylcholine
causes bladder contractions that leads to urination
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20. • Normally, the detrusor muscle remains at rest as the
bladder is filled by urine (filling phase).
• However, it contracts during the filling phase in patients
with OAB.
• Therefore, muscarinic receptor antagonists
(antimuscarinic agents) are considered the mainstay of
pharmacologic treatment for OAB
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21. Pharmacological Treatment
Medications that relax the bladder can be helpful for relieving symptoms
of overactive bladder and reducing episodes of urge incontinence.
These drugs include:
Tolterodine
Oxybutynin, which can be taken as a pill or used as a skin patch or gel
Trospium
Solifenacin
Fesoterodine
Mirabegron (Myrbetriq)
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22. Anticholinergic side effects
• Dry mouth – caused by reduced saliva
production is the most common side effect
• Constipation
• Dry eyes
• Blurred vision
• Indigestion or heartburn
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23. • Myrbetriq (mirabegron) is a beta-3 adrenergic
agonist indicated for the treatment of the
overactive bladder (OAB) condition.
• It was developed by Japan's Astellas Pharma.
• 2011
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24. Selective Beta-3 Adrenergic Agonist
medications
• Selective beta-3 adrenergic agonist medications were first released in
2014 in Australia for the treatment of overactive bladder.
• Mirabegron is the first drug of this class to be commercially available.
Mirabegron works by relaxing the smooth muscle of the bladder to allow
the bladder to store urine more easily.
• Mirabegron should not be used in people with severe uncontrolled high
blood pressure as it has the potential to increase blood pressure.
• People with well-controlled blood pressure on antihypertensive (blood
pressure lowering) medication can safely use Mirabegron.
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25. • The drug was approved in Japan in July 2011.
• The drug was approved by the US Food and Drug
Administration (FDA) in June 2012, for treating
the patients with OAB.
• Myrbetriq is the first oral treatment for OAB. It
was launched in US pharmacies in October 2012.
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26. • The drug is available in 25mg and 50mg
Extended Release form
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27. Development of mirabegron
• Initial interest in β3 receptors centred around their role in thermogenesis in
adipose tissue and potential for development as a treatment for obesity,which
proved a therapeutic dead end.
• However, investigation of the role of β3 in detrusor relaxation suggested that β3
agonists could be a useful therapeutic option for OAB, and mirabegron was
developed by Astellas Pharma Inc., Japan.
• Mirabegron is currently the only available β3 agonist.
• Mirabegron has been studied as both monotherapy and as combination therapy as
a treatment for OAB. At present, mirabegron is the only available β3 agonist,
although a second agent, vibegron, is undergoing phase III trials
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