PR3152 IC19 Flashcards
what is the physiology of the prostate
1) epithelial cells (glandular): growth stimulated by androgens
2) stroma cells (smooth): innervated by alpha1 adrenergic receptors
testosterone is converted into DHT by 5alpha-reductase.
what is the pathophysiology of BPH?
1) static component
- hormone factors (testosterone -> DHT) = enlargement of prostate tissue
2) dynamic component
- increase smooth muscle tissue and agonism of alpha 1 receptors = narrowing of urethra
= urethral obstruction and other s/sx
what is the pathophysiology of BPH in the long term, relating to bladder
the detrusor muscle must contract hard to force the urine out of the narrow urethra = hypertrophy = at the highest level of hypertrophy, the detrusor muscle compensates = bladder becomes irritative and highly sensitive = contract abnormally w/ smallest amounts of urine = increase urinary frequency.
what is LUTS
lower urinary tract symptoms (LUTS)
- nocturia, frequency, urgency, intermittent stream, straining, weak stream, incomplete emptying
progression of BPH in males? relate to age
more patients are asymptomatic until 65yo, where 1/3 will start to develop symptoms.
what are the two types of s/sx for BPH?
1) obstructive/voiding (typically early on)
- sensation of incomplete emptying
- dribbling
- weak stream
- intermittent stream
- hesitancy
- straining
2) irritative/storage (after several years, when detrusor starts to decompensated)
- frequency
- urgency
- nocturia
- dysuria (pain during urination)
- urinary incontinence
assessment methods for BPH
1) maximum urinary flow rate (Qmax)
2) Prostate specific antigen (PSA)
- not specific to BPH, but can monitor BPH progression. PSA ideally <1.5, may indicate risk of prostate cancer.
3) Post void residual (PVR)
- <100 = normal
- >200 = urinary retention
4) digital rectal exam (DRE)
5) ultrasonography
IPSS
7 sections, total of 5 per section, up to 35 max points
also includes QOL, up to 6 points.
MOH LUTS
4 grades
I) QOL <3, PVR < 100, treatment not needed
II) QOL ≥3 PVR <100, phx
III) QOLNIL PVR >100, Qmax<10ml/s surgical option
IV) QOLNIL, (urine retention, recurrent UTI, bladder calculi, persistent macroscopic hematuria)
surgery TURP
medication risk factors for BPH
need to remove risk factor
opioid analgesics = increases urinary retention
anticholinergics (tricyclic antidepressants eg -triptylines, antihistamines) = block acetylcholine which send signals for bladder contraction = reduces bladder muscle contractility
testosterone = increase prostate size
diruetics = increase urinary frequency
alpha 1 agonists (decongestants) = contract prostate smooth muscles
when do you not need to initiate treatment for BPH
if patient has IPSS < 8 or
mod-severe (IPSSS≥8) with QOL <3
non phx measures for bPH
1) limit fluid intake at night
2) avoid caffeine or alcohol intake
3) counsel patient to have complete and frequent urination
4) avoid meds that worsen symptoms
what to consider when initiating treatment for BPH
comorbidities
IPSS (luts severity)
prostate size
PSA
describe the alpha adrenergic antagonists (types, onset, and any specific instructions) in BPH
alpha1 adrenergic antagonists
1) non-selective: affect the peripheral vascular and urinary a1 receptors
- DTP: doxazosin, terazosin, prazosin (P not used)
- risk of hypotension and syncope = require dose titration slowly.
2) selective: selectively affect the urinary a1 receptors
- SAT: silodocin, alfuzocin, tamsulosin
- do not require dose titration.
onset is days to weeks
indication of alpha adrenergic antagonists in BPH
for patients with moderate to severe LUTS with small prostate <40g
downsides to alpha adrenergic antagonists in BPH
no effect on PSA
s/sx recur if discontinue
does not reduce prostate size or reduce progression of disease (only helps with symptomatic management)
benefits to alpha adrenergic antagonists in BPH
including onset time
fast onset of days to weeks
potentially beneficial in patients with concomitant HTN
side effect profile for alpha adrenergic antagonists in BPH
general: muscle weakness, fatigue, headache, ejaculatory abnormalities
uroselective: ejaculatory abnormalities
S>T>A
non-selective: dizziness, first dose syncope, hypotension
what medical condition to check when initiating alpha adrenergic antagonists and what to do w med admin in BPH
check for IFIS
- intraoperative floppy iris syndorms
caused by alpha adrenal blocking at the iris dilator muscle, complicates cataract surgery - likely cause = tamsulosin
to stop alpha blockers at least 14 days before surgery
administration instructions for non-selective alpha adrenergic antagonists in BPH
to take at night to reduce risk of orthostatic hypotension
what (and when) is the indication for 5ARIs in BPH
patients with moderate to severe LUTS and prostate size >40g
patients who cannot tolerate SE of alpha blockers OR do not want surgery
consider initiating if PSA >1.5
what are the 5ARI drugs in BPH
finasteride and dutasteride
benefits of 5ARI in BPH?
reduces PSA levels (consider initiating if PSA >1.5)
downsides of 5ARI in BPH?
slow onset 6-12months
side effect profile of 5ARI?
decreased libido
increased risk ejaculation abnormalities vs alpha blockers
erectile dysfunction
gynaecomastia
lesser HTN risk
5ARI increases the amount of circulating testosterone that (not converted to androgen) is now converted into estrogen, leading to development of female features = gynaecomastia
contraindications for 5ARI?
special population
women and children
additional labs to take before initiating 5ARI in BPH?
obtain PSA before starting as it is difficult to interpret after initiating
indications for PDE5i in BPH?
adjunctive therapy for BPH