Benign Prostatic Hyperplasia Flashcards
Signs of obstructive BPH
- Urinary hesitancy
- Urine dribbling
- Bladder fullness post voiding
(can be from static or dynamic factors)
Signs of irritative BPH
- Urinary frequency
- Urgency
- Nocturia
(these are from long-standing obstruction at the bladder neck)
Describe the 3 types of tissue in the prostate
- Epithelial - glandular tissue. Androgens stimulate growth (Stromal to epithelial tissue 2:1, 5:1 in BPH)
- Stromal tissue - smooth muscle tissue, alpha 1 adrenergic receptors (norepinephrine causes smooth muscle constriction)
- Capsule - fibrous connective tissue and smooth muscle (also has alpha 1 adrenergic receptors)
What is the principle testicular androgen?
testosterone
What is the principle adrenal androgen?
androstenedione
What are androgens converted to by 5 alpha reductase in target cells?
dihydrotestosterone (DHT)
What effect does DHT have on the prostate?
growth and enlargement
What is Type I 5-alpha reductase responsible for and where is it located?
Effects: acne and increased body and facial hair
Location: sebaceous glands in scalp, liver, and skin
What is Type II 5-alpha reductase responsible for and where is it located?
Effects: prostate, genital tissue (and hair follicles of scalp)
Location: DHT induces growth and enlargement of gland*
What medication type would help most quickly?
alpha-1 adrenergic antagonists
BPH: Static factors
- anatomic enlargement
- Androgen stimulation of epithelial tissue
BPH: Dynamic factors
- excessive alpha-adrenergic tone of stroma
- Results in contraction of prostate gland around urethra and narrowed urethral lumen
Name some drugs that can worsen BPH (4)
- Anticholinergic agents
- Antihistamines
- Tricyclic antidepressants
- Phenothiazines
What drug would block alpha1 - adrenergic receptors (non-selective)
Doxazosin (Cardura)
What drug blocks alpha 1-receptors selectively and is overall the preferred agent?
Tamsulosin (Flomax)
-also most expensive
What drug is a good fit for someone with BPH and ED?
Tadalafil (Cialis)
Which drugs need to be slowly titrated up to maintenance dose to minimize orthostatic hypotension and first-dose syncope?
- Doxazosin
- Terazosin
What drug would be best for reducing the static factor of BPH by blocking 5 alpha-reductase?
Finasteride (Proscar)
Dutasteride (Avodart)
Which 2 drugs relax the detrusor muscle of the bladder?
Oxybutynin (Ditropan)
Mirabegron (Myrbetriq)
Name two preventative benefits of using an alpha-1 adrenergic antagonist?
- Delay symptom progression
2. Reduce complications of BPH
What are some of the main downsides to using 5 alpha-reductase inhibitors? (5)
- SLOW onset (up to 6 months to see max benefit)
- Decreased libido
- Erectile dysfunction
- Ejaculation disorders
- Gynecomastia
What is an ADE affecting the eye for alpha-adrenergic antagonists (ex. Doxazosin, Tamsulosin)?
Floppy iris syndrome
What lab value is important to monitor with 5 alpha reductase inhibitors?
PSA, which should drop by 50% if adherent to therapy
Which two medications relax prostatic smooth muscle?
- Alpha-1 adrenergic antagonists (ex. Doxazosin and Tamsulosin)
- Phosphodiesterase inhibitors (ex. Tadenafil)
Which is the only medication that can decrease the prostate’s size?
5 alpha-reductase inhibitors (ex. Finasteride (Proscar), Dutasteride (Avodart))
Which is the only medication that lowers PSA?
5 alpha-reductase inhibitors (ex. Finasteride (Proscar), Dutasteride (Avodart))
Which 4 medications have potential for cardiovascular adverse effects?
- Alpha-1 adrenergic antagonists
- PDE inhibitors: mild hypotension
- Anticholinergic agents (tachycardia)
- Mirabegron (hypertension)
Which medication relaxes the detrusor muscle?
Mirabegron (Beta-3 adrenergic agonist)
What are the effects of Mirabegron (Beta 3 adrenergic agonist)
- reduces irritative voiding symptoms
- Increases bladder capacity
- Increases time between voidings
What is the best treatment option for a patient with BPH and a large prostate and irritative voiding symptoms?
alpha-1 adrenergic antagonist + anticholinergic
or
alpha-1 adrenergic antagonist + mirabegron
What is the best treatment for someone with BPH, without prostate enlargement and low PSA?
alpha-1 adrenergic antagonist
