OVERACTIVE BLADDER

1. Practical Approaches to
The Management of
Overactive Bladder
DR. Talal Ballout
Urologest

2. Bladder Properties
• Bladder is one of the most compliant organs of the body
• Should provide perfect continence
• Voluntary and efficient emptying at low pressure

3. Micturition Cycle
• Fill and store
• Empty completely
- simple but important phases
- important to help classify and treat disorders
of micturition

4. Bladder Filling and Storage
• Accommodates large volumes of urine
- maintains low intravesical pressure
(< 12 cm water)
- sustains sensation that is appropriate
• No involuntary contractions
- hyperreflexia, overactivity, reflex contractions or
instability
• Maintain a closed and continent outlet at rest
even with sudden intra-abdominal forces

5. Bladder Emptying
• Bladder contraction
- adequate magnitude
- sustained to empty
• Coordinated urethral relaxation
- bladder neck and proximal urethral smooth muscle
- striated external urethral sphincter
• No anatomic obstruction

6. Parasympathetic Muscarinic Receptors
• M1- neuronal, brain
• M2- cardiac, detrusor
• M3- detrusor, gastrointestinal smooth muscle, salivary
glands
• M4 + M5
• M3 receptors (20%) responsible for smooth muscle
contraction
• M2 receptors (80%) responsible for inhibition of smooth
muscle relaxation

7. Overactive Bladder
• Clinical term used to describe symptoms of frequency,
urgency, +/- urge incontinence
- term used without knowing specific cause of symptoms
(eg, detrusor overactivity)
• ICS 2002–Urgency with or without urge incontinence,
usually with frequency and nocturia
- absence of pathologic or metabolic conditions that might
explain these symptoms

8. Overactive Bladder Pathophysiology
• Multifactorial disorder
• A constellation of functional abnormalities
• 90% of cases idiopathic
• Can be caused by:
- neurologic defects
- myogenic defects

9. Overactive Bladder Neurologic Defects
• CVA
• Dementia (eg, vascular disease, Alzheimer’s,
encephalitis)
• Cerebral palsy
• Brain tumor
• Parkinson’s disease
• Multiple sclerosis
• Shy-Drager syndrome

10. Overactive Bladder and Spinal Cord
Injury
• Complete suprasacral lesions above T7
- detrusor hyperreflexia
- smooth sphincter dyssynergia
- striated sphincter dyssynergia
- no sensation
• Complete suprasacral lesions below T7
- detrusor hyperreflexia
- smooth sphincter synergy
- striated sphincter dyssynergia
- no sensation

11. Overactive Bladder Patient Evaluation
• History
• Physical
• Urodynamics
• Cystoscopy

12. History
• Urologic
• Ob/Gyn
• Neurologic
• Medical/surgical
• Social/psych
• Radiation
• Pelvic trauma

13. Incontinence History
• Characterization of incontinence
• Length and severity of symptoms
• Impact on quality of life
• Associated bowel problems

14. Physical Exam Women
• Systematic vaginal and pelvic exam
- condition of mucosa
- urethral mobility (Q tip test)
- demonstration of continence (CST)
- vaginal prolapse (anterior wall, posterior wall, apical)
- bimanual exam

15. Physical Exam
• Men–DRE and urogenital exam
• Neurologic exam
- mental status
- mobility
- lumbar and sacral sensory and motor
eg, BC reflex, anal wink, knee and ankle DTR’s

16. Ancillary Tests
• Voiding and intake diary
- Extremely important especially in cases of overactive
bladder
• Incontinence diary
• Urine analysis
- urine culture and cytology when indicated
• Post void residual
• Pad test

17. Role of Cystometry
• Defining underlying pathophysiology
- bladder filling
- involuntary detrusor contractions
- low bladder compliance
- urethral obstruction
- impaired detrusor contractility
• Directing treatment

18. Pharmacologic Treatment of Bladder
Overactivity
• Decrease detrusor activity
- abolish involuntary detrusor contractions
- increase volume at which they occur
- increase compliance
• Increase bladder capacity
• Commonly used agents focus on inhibition at the end
organ level

19. Pharmacologic Agents
Bladder Overactivity
• Antimuscarinics
• Muscle relaxants
• Mixed action drugs
• Tricyclic antidepressants
• Alpha blockers
• Beta agonists
• Vasopressin analogues

20. Antimuscarinics
• Antimuscarinics (anticholinergic) drugs have been the
mainstay of medical therapy for bladder overactivity
• Have been somewhat limited by the high incidence of
side effects and lack of selectivity

21. Mechanism of Action of Antimuscarinics
• Inhibit bladder contraction
- ACh from cholinergic nerves stimulate muscarinic
receptors
- block stimulation of muscarinic receptors

22. Antimuscarinic Agents of Common
Side Effects
• Dry mouth
• Constipation
• Drowsiness/somnolence
• Blurred vision/dry eyes

23. Antimuscarinics 2007
• Oxybutynin IR BID-TID
• Oxybutynin ER QD
• Oxybutynin TDS BIW
• Tolterodine IR/ER BID/QD
• Tropsium BID
• Solifenacin QD
• Darifenacin QD

24. What is the Difference?
• Efficacy
- no great differences
- dose-dependent
• Tolerability
• Safety
• Clinical effectiveness–different for different patients
depending on expectations

25. Imipramine
• Prominent systemic anticholinergic effects
• Weak antimuscarinic effects on the bladder
• Strong direct inhibitory effect on bladder smooth muscle
which is not anticholinergic or adrenergic
• Decreases contractility/increases outlet resistance
• Effects on lower urinary tract are additive to those of
atropine-like agents; useful in combo with other
anticholinergics
• Most common side effects
- anticholinergic effects, weakness, fatigue, sedation

26. Combination Pharmacotherapy
• Combination therapy–combining 2 drugs that have
different actions, eg, anticholinergic and tricyclic
• Intravesical instillation of Oxybutynin
- works best in cases where oral form is effective but
patients can’t tolerate side effects
- requires self-catheterization

27. Evaluation of Refractory
Overactive Bladder
• Post void residual
• Comprehensive urodynamic testing
• Cystoscopy
• Urine cytology
• Upper tract study
- renal ultrasound
- CT/MRI
- IVP
• Neurological evaluation, if necessary

28. Refractory Detrusor Overactivity
• Intravesical instillations–Capsaicin
• Botulinum-A Toxin
• Neuromodulation
- efficacy in neurogenic overactivity not universally
accepted
• Urinary reconstruction
- augmentation
- diversion

29. Conclusion
• Improved understanding of
pathophysiology
• Contribution of alternate neural receptors
• Better understanding of receptor action
and interaction
• Mechanism of action of antimuscarinics
and side effects