benign prostate hyperplasia Flashcards
what is the key hormone relating to the prostate
- testosterone converted to dihydrotestesterone (DHT) by type II 5 alpha reductase enzyme in the prostate
- DHT needed for normal growth or enlargement of prostate
how would you explain what BPH is
characterized by non-malignant growth of some components of the prostate resulting from hormonal factors and also vasoconstriction of smooth tissue muscles in the prostate gland when alpha1 receptors are activated
leads to urethral narrowing and obstruction
causing bladder muscle to decompensate and its maximal decompensation, the detrusor muscle becomes irritable and leads to LUTS
what are LUTS
obstructive/ voiding symptoms
- weak or intermittent stream
- dribbling
- sensation of incomplete emptying
- straining
- hesitancy
irritative/ storage symptoms
- frequency
- nocturia
- dysuria
- urgency
- urinary incontinence
how is BPH assessed
- digital rectal exam
- ultrasonography
- maximum urinary flow rate (Qmax)
- prostate specific antigen (PSA)
- postvoid residual volume (PVR)
- medication hx
which medications are of interest when taking medication hx
- anticholinergics (urinary retention by decreasing bladder muscle contractibility)
- alpha1 adrenergic agonist (contraction of prostate smooth muscles)
- opioids (increased urinary retention, impaired coordination, decreased bladder contractility, decreased sensation of fullness)
- diuretics (increases urinary frequency)
- testosterone (can stimulate prostate growth)
how to classify symptoms based on AUA-SI score
mild if ≤7 –> likely asymptomatic else mildly symptomatic
moderate if 8-19 –> obstructive and irritative symptoms
severe if ≥20 –> obstructive and irritative symptoms and at least one BPH complications
what are complciations of BPH
- recurrent UTI
- bladder stones
- acute urinary retention
- urinary incontinence
- blood in urine = hematuria
what is TURP and when is it indicated
transurethral resection of prostate is indicated with there is presence of BPH complications
what are the pharmacological management strategies of BPH
- watchful waiting for mild symptoms (AUA-SI <8) and moderate to severe symptoms but not bothered
- alpha antagonist
- 5ARI
- PDE5i
- antimuscarinics
what are non-pharmacological management of BPH
- limit fluid intake in evening
- avoid caffeine and alcohol as they are diuretic
- educate patient to take their time to completely empty their bladder and do so often so that there would not be residual urine to prevent triggering the bladder
- avoid medications that can exacerbate symptoms
what is the moa of alpha antagonist and list the drugs in this class
non selective alpha antagonists (terazosin)
- antagonises both peripheral vascular and urinary alpha1 adrenergic receptors
selective alpha antagonists (tamsulosin, alfuzosin)
- selectively antagonises urinary alpha1 receptors which is the predominant receptor in prostate and lower urinary tract
what are the s/e of alpha1 antagonists
- hypotension (esp for non selective, titrate slowly, bedtime administration to reduce risk of OH), muscle weakness, fatigue, HA, ejaculatory disturbance
- intraoperative floppy iris syndrome assoc w tamsulosin due to blockade of alpha1 in iris dilator muscle
what is the role of therapy place in therapy of alpha1 antagonists
- for reducing LUTS especially in moderate to severe with small prostate <40g
- not for prostate size reduction and reducing risk of progression
- onset fast as just dilation
what is the moa of 5ARIs and list the drugs in this class
finasteride, dutasteride
- inhibit 5 alpha reductase type II to decrease conversion of testosterone to DHT to reduce the size of prostate and slow progression of disease and reduce the need for surgery
what are the s/e of 5ARIs
- ejaculatory disturbance, decreased libido (due to reduced testosterone), erectile dysfunction, gynaecomastia, breast tenderness
