Overactive Bladder Flashcards
Which muscarinic receptor is responsible for both emptying contractions as well as involuntary bladder contractions of incontinence?
M3 receptors
Whats overactive bladder (OAB)?
Urinary urgency (a sudden, compelling desire to pass urine which is difficult to defer)
+
Urinary freq (voiding >= 8 times in a 24 ht period)
+
Nocturia (>= 2 awakenings to void per night)
Which muscle is overactive in overactive bladder!
Detrusor muscle is hyperactive, causing the sx of freq micturitions, urgency, nocturia and/or incontinence
Risk factors for OAB?
Age > 40 yrs
DM
Restricted mobility
Obesity
Prior vaginal delivery
Neurologic conditions (eg stroke, Parkinson’s dx, dementia)
Hysterectomy
Drugs that can increase incontinence (ACE-I (due to cough), cholinesterase inh, diuretics)
Pelvic injury
Forms of urinary incontinence?
Functional
Overflow
Stress
Urge
Mixed
What’s Functional urinary incontinence?
No abnormality in the bladder, but pt may be cognitively, socially or physically impaired thus hindering him or her from access to a toilet (eg pts in wheelchair)
What’s Overflow urinary incontinence?
Leakage that occurs when quantity of urine stored in bladder exceeds its capacity, often occurring w/o the urge to urinate
BPH is the most common cause
What’s Stress urinary incontinence?
Urinary leaks out during any form of exertion (eg exercise, coughing, sneezing, laughing etc) as a result of pressure on bladder
What’s Urge urinary incontinence?
Pt can’t hold in urine long enough to reach the toilet and is associated with neuropathy
What’s Mixed urinary incontinence?
Combination of urge and stress incontinence
Approx 1/3 of incontinence is stress, 1/3 is urge, 1/3 is mixed
Non-pharmacologic therapy for OAB?
They are first-line tx
Pelvic floor muscle (Kegel) exercise
Pharmacologic therapy for OAB?
Anticholinergic drugs are 2nd line therapy (antagonists of muscarinic receptor and block acetylcholine this limiting contractions of detrusor muscle)
What type of anticholinergic formulation is preferred? Why?
Extended-release formulations
Due to lower rate of dry mouth
Effects of cholinergic drugs?
Act like acetylcholine and cause SLUD sx
Salivation
Lacrimation (tearing)
Urination
Diarrhea
What may be used to treat urinary retention?
Bethanecol (causes urination)
Pilocarpine (another cholinergic) used for dry mouth (to increase salivation)
