IC18 BPH + ED Flashcards
What is the definition of BPH? (3 points)
Benign Prostatic Hyperplasia
Definition:
- Lower urinary tract signs and symptoms (LUTS)
- Negatively impact on QOL
- Non-malignant growth of prostate components e.g. transitional zone
What is the physiology of the prostate?
Physiology of prostate:
- Epithelial (glandular) tissue –> androgens stimulate its growth
a. Testosterone is converted to dihydrotestosterone (DHT) by Type II 5α-reductase in prostate
b. DHT is needed in normal growth and enlargement of prostate - Stromal (smooth muscle) tissue –> innervate by α1 adrenergic receptors
What is the pathogenesis of BPH?
Pathogenesis
- Mainly age and hormonal factors
- Static component:
Hormonal factors
testosterone –> DHT
Enlargement of prostate tissue - Dynamic Component:
Increase smooth muscle tissue and agonism of α1-receptors (vasoconstriction)
Narrowing of urethra outlet
–> Urethral obstruction / Signs and symptoms
Long Term
- Bladder response to obstruction
o Early phase: bladder muscle force urine through narrowed urethra by contracting more forcefully
o Over time: bladder muscle gradually becomes thicker (hypertrophy) to overcome obstruction
o Once reach highest state of hypertrophy, muscle decompensates
o Detrusor muscle becomes irritable and/or overly sensitive (detrusor overactivity or instability), contracting abnormally in response to small amounts of urine –> increase frequency of urine
What are the S&S of BPH?
Signs and Symptoms
Commonly asymptomatic, symptoms only occur in 1/3 men who are >65y/o
LUTS:
- Weak stream
- Increase frequency
- Nocturia
- Intermittent stream (urinary stream is not continuous)
- Incomplete emptying
- Straining
- Increase urgency
*LUTS not specific to BPH, other things can cause LUTS
e.g. prostate/bladder cancer, UTIs, diabetes mellitus
Obstructive /Voiding Symptoms
(early BPH):
- Hesitancy
- Weak stream
- Sensation of incomplete emptying
- Dribbling
- Straining
- Intermittent flow
Irritative/Storage symptoms
(Late BPH)
[Occurs after several years of untreated BPH]:
- Dysuria
- Nocturia
- Increase frequency (overly sensitive so can’t control when you have a small amt of urine)
- Increase urgency
- Urinary Incontinence (loss of bladder control, involuntary peeing)
What are the classifications of symptoms (severity) for BPH?
Severity AUA – SI score Usual Signs and Symptoms:
- Mild <= 7 Asymptomatic or mildly symptomatic
- Moderate 8-19 All of the above s/s AND Have obstructive voiding and irritable voiding symptoms
- Severe >= 20 Signs and symptoms AND complications
Complications:
- Recurrent UTI
- Bladder stones
- Acute urinary retention
- Urinary incontinence
- Hematuria
(Consider transurethral resection of prostate (TURP) when have complications)
What are the test and cut offs when evaluating BPH?
Assessment of BPH:
- Digital Rectal exam – normal prostate should be smooth
- Ultrasonography
- Maximum urinary flow rate (Qmax) – if there is some sort of obstruction, will have weak stream
- Prostate Specific Antigen (PSA)
a. The bigger the prostate, the higher the PSA
b. Predict progression of BPH –> PSA > 1.5 ng/mL
c. Higher risk of prostate cancer - Postvoid Residual (PVR)
a. <100 mL normal
b. >200 mL – inadequate emptying
What are the medications that can worsen BPH? (5 meds)
- Anticholinergics
e.g. antihistamines, tricyclic antidepressants, anti-muscarinic
- Decrease bladder muscle contractability -> increase urinary retention
- Alpha1 adrenergic agonist e.g. decongestant
- Contraction of prostate smooth muscles
- Opioid analgesic –> Increase urinary retention
- Diuretics –> Increase urine frequency
- Testosterone –> Increase prostate growth
When to start therapy for BPH? What to do if mild symptoms?
Management + when to start pharmacological therapy:
- As long as BPH does NOT affect QOL/not bothered, just watch and assess annually + non-pharm (be it mild, moderate or severe)
- START medications when moderate to severe and are bothered by symptoms
- Assess using AUA-SI score annually
- Advise regarding non-pharmacological
What are the non-pharm management of BPH?
Non-pharmacologicals
- Drink less water in the evening –> reduce urine frequency
- Eat less caffeine and drink less alcohol –> reduce urine frequency
- Take time to completely empty bladder
- Avoid medications that worsens BPH (anticholinergics, alpha receptor agonist, opioids analgesics, diuretics, testosterones)
What is the MOA of alpha 1 Receptor antagonist?
MOA
Mod-severe with small prostate (<40g)
Reversibly inhibit alpha1 adrenergic receptors
–> reduce smooth muscle contraction and cause vasodilation (dynamic component)
Non-selective (blood vessels, heart, peripheral, LUT)
- E.g. Doxazosin, Terazosin, Prazosin (not reco in BPH)
- Titrate dose slowly –> due to hypotension and syncope
Uroselective (blood vessel, prostate, LUT)
- E.g. Alfuzosin, Tamsulosin, Silodosin
NO effect on prostate size, prevention of BPH progression, need for surgery and PSA
Fast onset (days to weeks)
What are the non-selective alpha blockers?
Doxazosin, terazosin, prazosin
What are the uro-selective alpha blockers?
Alfuzosin, tamsulosin, silodosin
What are the ADRs of the class, non-selective and selective alpha blockers?
ADR
- Muscle weakness
- Fatigue
- Ejaculatory disturbance
- Headache (thus give bedtime dose)
Non-selective:
- Orthostatic hypotension
- 1st dose Syncope
- Dizziness
Uroselective:
- Ejaculatory disturbances (delayed or retrograde ejaculation)
- Silodosin > Tamsulosin > Alfuzosin
- (Tamsulosin) Intraoperative floppy iris syndrome
- CI in cataract surgery
- Block a1 receptors in iris dilator muscle
- Avoid starting until surgery is complete
What are the special considerations for using non-selective alpha blockers and selective alpha blockers?
Special Considerations
- Non-selective ARA:
o Use if need additional blood pressure lowering effect
o Avoid in patients at risk of syncope
o Should NOT be given as monotherapy for patients with BPH and HTN, need give with other meds - Selective ARA
o Used if don’t need extra anti-hypertensive effects
When to consider adding 5aRI? What is the MOA of 5aRI?
MOA
Mod-severe with large prostate (>40g)
Consider adding if PSA > 1.5ng/mL
Competitively bind to 5alpha reductase
- prevent the conversion of testosterone to DHT by 5alpha reductase
- less DHT
- reduce size of prostate (static component) + slows BPH progression + need for surgery
- Reduces PSA (obtain PSA before starting therapy)
E.g. Finasteride, dutasteride
Slow onset (6 months to a year)
What is the ADR of 5aRI?
ADR (More sexual dysfunction that Alpha1 ARA)
- Ejaculatory disorders
- Loss of libido
- ED (due to less DHT)
- Gynecomastia and breast tenderness
What is the CI for 5aRI?
Special Considerations CI:
- Women, children, pregnancy
Which PDE5i is used for BPH? How is PDE5i often used in clincial practise for BPH?
ONLY Tadalafil allowed for BPH
Adjunct therapy for BPH