URINARY INCONTINENCE

A   58-year-old woman   complains   of  urinary leakage after   exertion.   She loses

urine   while   coughing,   sneezing,   and playing golf.   She underwent

menopause   five    years   ago and is  not on  estrogen    therapy.    On  examination

there   is  evidence    of  urethral    hypermobility   with    a   positive    Q-tip   test.

Urinary incontinence is the inability to hold urine, producing involuntary urinary
leakage.

The physiology of continence can be explained as follows:

The pharmacology of incontinence can be explained as follows:

Continence  and micturition involve a   balance between urethral    closure and

detrusor    muscle  activity.   Urethral    pressure    normally    exceeds bladder pressure,

causing urine   to  remain  in  the bladder.    

The proximal    urethra and bladder are normally    both    within  the pelvis.

Intraabdominal  pressure    increases   (from   coughing    and sneezing)   are

transmitted to  both    urethra and bladder equally,    leaving the pressure

differential    unchanged,  resulting   in  continence. Normal  voiding is  the result

of  changes in  both    of  these   pressure    factors:    urethral    pressure    falls   and

bladder pressure    rises.  

Spontaneous bladder muscle  (detrusor)  contractions    are normally    easily

suppressed  voluntarily.

α-adrenergic    receptors   are found   primarily   in  the urethra and when