Micturition

From a therapeutic point of view, it is essential to confirm the presence of bacteriuria (a condition in which there are bacteria in the urine) since symptoms alone are not a reliable method of documenting infection. This applies particularly to bladder infection where the symptoms of burning micturition (dysuria) and frequency can be associated with a variety of non-bacteriuric conditions. Patients with symptomatic bacteriuria should always be treated. However, the necessity to treat asymptomatic bacteriuric patients varies with age and the presence or absence of underlying urinary tract abnormalities. In the pre-school child it is essential to treat all urinary tract infections and maintain the urine in a sterile state so that normal kidney maturation can proceed. Likewise in pregnancy there is a risk of infection ascending from the bladder to involve the kidney. This is a serious complication and may result in premature labour. Other indications for treating asymptomatic bacteriuria include the presence of underlying renal abnormalities such as stones which may be associated with repeated infections caused by Proteus spp. 

Capsaicin-sensitive nerves sense bladder fullness and form the afferent limb of the micturition reflex [132]. In conditions of bladder hypersensitivity, TRPVl is up-regulated on these nerves (presumably via NGL [133, 134]) and deafferentation of the bladder by intravesical capsaicin or RTX was proven beneficial [135-137]. Parenthetically, intravesical RTX is also an effective analgesic agent during experimental cystitis in the rat [138]. By... 

Urinary frequency (greater than 8 micturitions/day), urgency with or without urge incontinence nocturia (greater than or equal to 2 micturitions/night) and enuresis may be present as well. 

Frequency from urge onset to micturition Yes/no, daytime/nighttime/both, how often... 

Enhancing the positive effects of serotonin and norepinephrine in the afferent and efferent pathways of the micturition reflex... 

Monitor the patient for symptom relief. Have the desired outcomes jointly developed by the health care team and the patient/caregiver been achieved and to what degree Inspect the daily diary completed by the patient/caregiver since the last clinic visit and quantitate the clinical response (e.g., number of micturitions, number of incontinence episodes, and pad use). If a diary has not been used, ask the patient how many incontinence pads have been used and how they have been doing in terms of accidents since the last visit. If appropriate, administer a short-form instrument used to measure symptom impact and condition-specific quality of life and compare previous result(s). 

Locally invasive prostate cancer is associated with ureteral dysfunction or impingement, such as alterations in micturition (e.g., urinary frequency, hesitancy, dribbling). 

Acetylcholine is the neurotransmitter that mediates both volitional and involuntary contractions of the bladder. Bladder smooth muscle cholinergic receptors are mainly of the M2 variety however, M3 receptors are responsible for both emptying contraction of normal micturition and involuntary bladder contractions, which can result in UI. Therefore, most pharmacologic antimuscarinic therapy is anti-M3 based. 

The goal of treatment of SUI is to improve urethral closure by stimulating a-adrenergic receptors in the smooth muscle of the bladder neck and proximal urethra, enhancing supportive structures underlying the urethral epithelium, or enhancing serotonin and norepinephrine effects in the micturition reflex pathways. 

Six placebo-controlled studies showed that duloxetine reduces incontinent episode frequency and the number of daily micturitions, increases micturition interval, and improves quality-of-life scores. These benefits were statistically significant but clinically modest. 

Oxybutynin extended-release is better tolerated than oxybutynin IR and is as effective in reducing the number of UI episodes, restoring continence, decreasing the number of micturitions per day, and increasing urine volume voided per micturition. 

Controlled studies demonstrate that tolterodine is more effective than placebo and as effective as oxybutynin IR in decreasing the number of daily micturitions and increasing the volume voided per micturition. However, most studies have not shown a decrease in the number of daily UI episodes as compared with placebo. 

Reproductive disorders Endometrial disorder Leukorrhea Uterine disorder Uterovaginal prolapse Vaginal discomfort Urinary system disorders Micturition frequency Urinary incontinence Gastrointestinal disorders Abdominal pain Constipation... 

In benign hyperplasia of the prostate, a-blockers (terazosin, alfuzosin) may serve to lower tonus of smooth musculature in the prostatic region and thereby facilitate micturition (p. 252). 

Responses to activation of the parasympathetic system. Parasympathetic nerves regulate processes connected with energy assimilation (food intake, digestion, absorption) and storage. These processes operate when the body is at rest, allowing a decreased tidal volume (increased bronchomotor tone) and decreased cardiac activity. Secretion of saliva and intestinal fluids promotes the digestion of foodstuffs transport of intestinal contents is speeded up because of enhanced peristaltic activity and lowered tone of sphincteric muscles. To empty the urinary bladder (micturition), wall tension is increased by detrusor activation with a concurrent relaxation of sphincter tonus. 

Prostatic hypertrophy with impaired micturition loss of parasympathetic control of the detrusor muscle exacerbates difficulties in voiding urine. 

The side effects of tricyclic antidepressants are largely attributable to the ability of these compounds to bind to and block receptors for endogenous transmitter substances. These effects develop acutely. Antagonism at muscarinic cholinoceptors leads to atropine-like effects such as tachycardia, inhibition of exocrine glands, constipation, impaired micturition, and blurred vision. 

Finasteride inhibits 5a-reductase, the enzyme converting T. into dihydrotestosterone (DHT). Thus, the androgenic stimulus is reduced in those tissues in which DHT is the active species (e.g., prostate). T.-dependent tissues or functions are not or hardly affected (e.g., skeletal muscle, negative feedback inhibition of gonadotropin secretion, and libido). Finasteride can be used in benign prostate hyperplasia to shrink the gland and, possibly, to improve micturition. 

Significant adverse reactions include fatigue headache drowsiness paresthesias difficulty in micturition diarrhea reversible increases in serum transaminases dyspnea bronchospasm asthenia muscle cramps nausea vomiting fever with aching and sore throat toxic myopathy rashes systemic lupus erythematosus vision abnormality hypoesthesia ventricular arrhythmias intensification of AV block mental depression scalp tingling. 

Urinary system disorders Initiation of neuraxial opiate analgesia is frequently associated with disturbances of micturition, especially in males with prostatic enlargement. 

Blurred vision, confusion, constipation, hallucinations, delayed micturition, eye pain, arrhythmias, fine muscle tremors, parkinsonian syndrome, anxiety, diarrhea, diaphoresis, heartburn, insomnia Rare... 

Mechanism of Action A cholinergic that acts directly at cholinergic receptors in the smooth muscle of the urinary bladder and GI tract. Increases detrusor muscle tone. Therapeutic Effect May initiate micturition and bladder emptying. Improves gastric and intestinal motility. 

Somnolence, fatigue, dry mouth, blurred vision, constipation, sexual dysfunction (42%), ejaculatory failure (20%), impotence, weight gain (18%), delayed micturition, orthostatic hypotension, diaphoresis, impaired concentration, increased appetite, urine retention Occasional... 

Rash, micturition disorder (polyuria, nocturia, dysuria, frequency of urination), abdominal discomfort, somnolence... 

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