Urinary tract Flashcards
bladder fucntion
The urinary bladder has two types of muscles: the detrusor muscle, a muscle that encircles the body of the bladder and the bladder sphincter, a muscle group in a ringed shape
at the neck of the bladder.
• In a relaxed state, the detrusor muscle acts to store urine while in a contracted state, the detrusor muscle acts to empty the bladder.
• A third group of muscles, the, act to improve the urinary sphincter tone resistance when the pelvic floor muscles are in a contracted state.

The urinary bladder function cont
- When the detrusor muscle of the bladder contracts, the bladder sphincter muscles responsively relax, thus allowing for normal urination.
- The binding of acetylcholine to muscarinic receptors within the smooth muscle which surrounds the bladder normally results in muscular contraction and emptying of urine from the bladder into the urethra.
Incontinence
- Urinary incontinence is the involuntary loss of urine.
- There are 4 main types of urinary incontinence:
- Stress Incontinence (MC)
- Urge Incontinence
- Overflow incontinence
- Functional incontinence
Stress incontinence
- Stress incontinence is characterized by the loss of small amounts of urine with coughing, laughing, sneezing, exercising or other movements that increase intraabdominal pressure and thus increase pressure on the bladder.
- Stress incontinence is generally due to weakness in the pelvic floor musculature.
Stress incontinence tx
- The best treatment for stress incontinence consists of strengthening the pelvic wall musculature. Kegel exercises are the initial treatment of choice.
- Oral or vaginal estrogen therapy can be utilized to improve pelvic floor strength and the benefits vs. risks of therapy should be reviewed on a patient by patient basis.
• Other options include pelvic floor physical therapy, electrical stimulation, biofeedback and, if necessary, surgery.

Urge incontinence
- Urge incontinence is the involuntary loss of urine due to an overactive detrusor muscle.
- The terms “spastic bladder” or “overactive bladder” both refer to urge incontinence.
- Detrusor overactivity can occur as a result of infection, inflammation or irritation of the bladder.
- Neurogenic detrusor overactivity implies a defect in the CNS inhibitory response.
Urge incontinence etiol
- Cystitis is the most common cause of transient urge incontinence.
- Irritation of the bladder wall by the infected urine can cause repeated contractions of the detrusor muscle.
- Detrusor spasm can be perceived as a sense of urgency to urinate, even when the volume of urine is small, as well as an increased frequency of urination.
can also occur because of impaired or altered innervation to the bladder related to such conditions as spinal cord injuries, stroke, Multiple Sclerosis, Parkinson’s disease and other CNS diseases.
Urge incontinence meds
• Several medications are available that
block acetylcholine action on the bladder and diminish detrusor muscle contraction.
- Examples of this group of medications include Oxybutynin and Tolterodine.
- Tricyclic antidepressents are also used to decrease bladder spasm.
Oxybutynin/ Ditropan
- Class: Anticholinergic medication
- Indication: Used to relieve frequent urination and inability to control urination due to urge incontinence. Also used for hyperhidrosis (hyper-active sweating).
- MOA: Competitive antagonism of M3 subtype of the muscarinic acetylcholine receptor. Oxybutynin has direct antispasmotic effects on bladder smooth muscle as a calcium antagonist and local anesthetic, but at concentrations far above those used clinically.
also gluten free diet is great! food sensitivities in general
Oxybutynin/ Ditropan SE
- Char: PO, usually dosed BID or DID, before or with meals.
- Side effects: dry mouth, dry eyes, constipation, blurred vision, drowsiness dizziness and diminished sweating. Patients taking this medication should be instructed to use extra care not to become overheated during exercise to avoid the risk of heat stroke.
Oxybutynin is metabolized by the cytochrome P450 enzyme system.
Tolterodine/ Detrol
- Class: Anticholinergic medication
- Indication: Used to relieve frequent urination and inability to control urination due to urge incontinence.
- MOA: Competitive antagonism of M2 and M3 subtypes of the muscarinic acetylcholine receptor.
advantage of fewer side effects, less dosing
Tolterodine/ Detrol is metabolized by the cytochrome P450 enzyme system.
Imipramine/ Tofranil
- Class: Tricyclic antidepressant, mainly used in the treatment of clinical depression but is also used in cases of urge incontinence and enuresis.
- MOA: Blocks reuptake of serotonin and norepinephrine and appears to diminish acetylcholine uptake in smooth muscle.
- Char: As a medication for incontinence, Imipramine is given at bed time for enuresis.
utilized more in peds
Imipramine/ Tofranil SE
- Side effects: Dry mouth, blurred vision, constipation, insomnia, flushing, tremulousness and weight gain. Agitation, irritability, confusion, and delirium are also possible, particularly in the elderly.
- Similar to other anti-depressant drugs, there is now a black box warning about increased risk for suicidal ideation and suicide.
• Overdose can be fatal due to heart block.

Overflow incontinence
- Overflow incontinence occurs when the increased bladder pressure due to retained urine exceeds the pressure of resistance exerted by the sphincter muscles and pelvic floor musculature.
- In men, overflow incontinence is most often associated with benign prostatic hyperplasia/hypertrophy.
Autonomic neuropathy from diabetes mellitus or other diseases such as Multiple Sclerosis can decrease neural signals from the bladder (allowing for overfilling) and may also diminish neural input to the detrusor muscle (allowing for urinary retention).
• Medication used in the treatment of autonomic neuropathy related incontinence has been unsatisfactory.

Benign prostatic hyperplasia/ hypertrophy
- The two main medications for management of BPH are alpha blockers and 5α-reductase inhibitors.
- Alpha blockers relax smooth muscle in the prostate and in the bladder neck, thus potentially increasing flow of urine.
• Common side effects of alpha blockers include orthostatic hypotension, fatigue and nasal congestion.

