Urology Flashcards
What are the four types of urinary incontinence?
- urgency: associated with overactive bladder syndrome
- stress: due to urethral sphincter incompetence
- mixed: urgency and stress
- overflow: continuous urine leakage, often resulting from a hypotonic bladder or from a bladder outlet obstruction producing retention
What pharmacological treatments are available for urgency incontinence and overactive bladder syndrome?
Muscarinic receptor antagonists (act on the PSNS):
- oxybutinin
- tolderodine
Beta3-adrenoreceptor agonists (act on the SNS):
- mirabegron
What are the side effects of muscarinic blockade (e.g. oxybutinin treatment)?
- dry mouth
- tachycardia
- constipation
- blurred vision
- urinary retention
What are the recommended treatments for stress incontinence?
- pelvic floor muscle training
- surgical intervention (surgical sling / colposuspension)
- drug therapy is limited (vaginal oestrogens, duloxetine) and only recommended if patient not for surgery
How do you asses the severity of BPH?
International prostate severity score
What is the mechanism of action of alpha blockers in BPH?
Alpha blockade induces smooth muscle relaxation so causes vasodilation and the fall in blood pressure reduces prostatic resistance to bladder outflow
What adverse drug effects can alpha blockers have?
- orthostatic hypotension (particularly the first dose)
- headache
- dizziness
- ED
- rhinitis
- asthenia
- oedema
If a man presents with LUTS, has a large prostate and is considered to be at high risk of progression to malignancy, what is the first line treatment?
A 5alpha reductase inhibitor
- dutasteride
- finasteride
A combination of alpha blocker and 5alpha reductase inhibitor may be offered
What factors would put a man with a large prostate at greater risk of progression to malignancy?
- age
- poor urine flow
- higher symptom scores
- evidence of bladder decompensation (e.g. chronic urinary retention)
- higher PSA
What is the mechanism of action of 5alpha reductase inhibitors in BPH?
- 5alpha reductase catalyzes the conversion of testosterone to dihydrotestosterone in the prostate
- inhibitors reduce the size of the prostate gland by limiting the availability of dihydrotestosterone
What are the potential adverse effects of 5alpha reductase inhibitors?
- gynaecomastia
- decreased libido
- ejaculation disorders
- impotence
What are the important cautions to give when prescribing 5alpha reductase inhibitors?
- verapamil and diltiazem increase concentrations of dutasteride
- in-utero exposure to 5alpha reductase inhibitors can cause genital malformations in the male foetus - pregnant women should not take them, handle them or be exposed to semen from a man who is taking them