BPH, ED, OAB

Question 1

Drug Classes used to treat BPH

Answer 1

Alpha 1 Antagonists
5 alpha reductase inhibitors
PDE5 inhibitors (3rd line)

Question 2

Alpha Blocker MOA

Answer 2

block alpha1 receptors in the vasculature resulting in arterial and venous vasodilation
Alpha-1 receptors are densely located in the bladder neck and prostate = relaxation of the smooth muscle and decreased urethral resistance

Question 3

Alpha blocker side effects

Answer 3

Major side effect: hypotension
Potentiated by PDE-5 inhibitor use – space dosing by at least 4 hours

Other side effects: headache, dizziness, nasal congestion, fluid retention, impotence, palpitations, drowsiness

Question 4

Alpha blocker examples

Answer 4

Doxazosin, terazosin - older, require titration, inexpesive, greater risk of orthostatic hypotension
Alfuzosin, tamsulosin, silodosin - no titration needed

Question 5

Which alpha blocker must be stopped prior to cataract surgery and why?

Answer 5

Tamsulosin d/t risk of floppy iris syndrome

Question 6

Alpha blocker off label use

Answer 6

renal stones

Question 7

5 alpha reductase inhibitors MOA

Answer 7

5-alpha reductase converts testosterone to dihydrotestosterone (DHT)

DHT stimulates proliferation of prostate cells and decreases prostate cell apoptosis

Question 8

5 alpha reductase inhibitor examples

Answer 8

finasteride - also used for hair loss at lower doses

dutasteride

Question 9

5 alpha reductase inhibitor side effects

Answer 9

3-6 months for maximal effect
Side effects: decreased libido, impotence, decreased semen quantity
Will decrease serum PSA by ~50% – important if you are monitoring for changes

Question 10

Common meds that can exacerbate BPH

Answer 10

TCAs, anticholinergics, decongestants, antihistamines, antipsychotics, muslce relaxants, amphetamines, hormones

Question 11

PDE5 inhibitor indication and MOA

Answer 11

Indications: erectile dysfunction, pulmonary HTN, BPH

MOA: PDE-5 converts cGMP to GMP resulting in increased levels of cGMP.
cGMP dilates blood vessels in the lungs and genitalia - necessary for erection to occur

Question 12

PDE 5 inhibitor examples

Answer 12

Sildenafil (Viagra)
Tadalafil (Cialis)
Vardenafil (Levitra)
Avanafil (Stendra)

Question 13

PDE 5 inhibitors adverse effects/patient education

Answer 13

SE: Priapism, visual disturbances, hearing loss

Typically taken 30-60 min before intercourse

Question 14

PDE5 inhibitors contraind/cautions

Answer 14

Contraindications
Anyone taking nitrates
MI/stroke or life threatening arrhythmia within the last 6 months
Use caution with HF, hypo or uncontrolled hypertension, unstable angina, prolonged QT, alpha blocker use

Question 15

Anticholinergics for OAB MOA and examples

Answer 15

Inhibit detrusor muscle contraction

Oxybutynin (Ditropan)
Tolterodine (Detrol)
Solifenacin (VESIcare)
Darifenacin (Enablex)
Trospium (Sanctura)
Fesoterodine (Toviaz)

*XR formulations are preferred = less side effects

Question 16

Anticholinergic side effects/contraindications

Answer 16

Urinary retention, dry mouth*, constipation, dizziness, blurry vision, tachycardia, drowsiness

Contraindicated in narrow angle closure glaucoma, uncontrolled tachycardia
Increase dementia risk