BPH Flashcards
What are the 3 types of tissue in the prostate gland?
- epithelial
- stromal
- capsule
What stimulates epithelial growth?
Androgens
What is stromal tissue embedded w/?
Alpha1-adrenergic receptors
What is the capsule embedded w/? What does norepinephrine do?
Alpha1-adrenergic receptors
- When stimulated w/ norepinephrine, the capsule contracts around the urethra
Testosterone is the principal…
testicular androgen
Androstenedione is the principal…
adrenal androgen
Androgens are converted into what?
5α-reductase converts androgens to DHT, an active metabolite
What is considered a more potent androgen than testosterone?
DHT
What does DHT do?
Induces growth & enlargement of the prostate
What are the 2 types of 5α-reductase?
- Type I enzyme: causes acne & increased hair
- Type II enzyme
What is a normal prostate composed of?
- Higher amounts of stromal tissue than epithelial, Ratio = 2:1
What is the stromal-to-epithelial tissue ratio in BPH?
5:1
What is the MOA of 5α-reductase inhibitors in epithelial tissue?
Reduce an enlarged prostate by 25%
What is the MOA of alpha1-adrenergic receptors in stromal tissue?
SM contraction in enlarged prostate & bladder base obstructing urine flow
What med is quickly effective in sx management of urinary flow?
alpha1-adrenergic antagonists
What do static factors relate to?
Enlargement of prostate
- Depends on androgen stimulation of epithelial tissue & estrogen stimulation of stromal tissue
What do dynamic factors relate to?
Excessive α-adrenergic tone of the stromal component –> contraction of prostate around urethra & narrowing of urethral lumen
Which factors are responsible for obstructive voiding sx?
Dynamic!
What 3 agents reduce the dynamic factor in BPH?
- Doxazosin (Cardura)
- Tamsulosin (Flomax)
- Tadalafil (Cialis)
Which agent reduces the static factor in BPH?
Finasteride (Proscar)
What 2 agents relax the detruser muscle of the bladder?
- Oxybutynin (Ditropan)
- Mirabegron (Myrbetrig)
Older 2nd-generation immediate-release α1-Adrenergic Antagonists can cause…
Adverse CV effect
5α-Reductase Inhibitors are useful primarily for patients with…
large prostates
Which class of meds has a slow onset of action?
5α-Reductase Inhibitors
- Takes up to 6 months!
What are 4 adverse effects of 5α-Reductase Inhibitors?
- Decreased libido
- ED
- Ejaculation disorders
- Gynecomastia
What 2 vitals should you monitor w/ α-Adrenergic antagonists?
BP & HR
How do you administer 1st dose of α-Adrenergic antagonists?
Start on lowest dose, take at bedtime
What is a contraindication of α-Adrenergic antagonists?
Cataract surgery
What is a complication of α-Adrenergic antagonists?
Painful erection lasting longer than 4 hrs
What is an ADE of α-Adrenergic antagonists?
Floppy iris syndrome
What lab should you monitor w/ 5α-Reductase Inhibitors?
PSA
- Should decrease by 50%
What is the peak onset of α-Adrenergic antagonists?
1-6wks
Phosphodiesterase inhibitors vs anticholinergic agents
- PD inhibitors: Relax SM
- Anticholinergic ADE: ED
- Both have CV ADEs
What is are ADEs of β3-adrenergic agonists (Mirabegron)?
- HTN (CV ADE)
- Impaired cognition
What 2 things should you monitor w/ β3-adrenergic agonists (Mirabegron) ?
BP & bowel habits
