Practical Approaches to The Management of Overactive Bladder

1
Practical Approaches to The Management of
Overactive Bladder

• Donald A. Culley MD, PhD, FACS
• South Atlanta Urology and Gynecology

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
• (lt 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 2002Urgency 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, Alzheimers,
  encephalitis)
• Cerebral palsy
• Brain tumor
• Parkinsons 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

• MenDRE and urogenital exam
• Neurologic exam
• - mental status
• - mobility
• - lumbar and sacral sensory and motor
• eg, BC reflex, anal wink, knee and ankle DTRs

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 effectivenessdifferent 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 therapycombining 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 cant 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 instillationsCapsaicin
• 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