Benign Prostatic Hyperplasia (BPH)

Question 1

BPH physiology and pathophysiology

Answer 1

Testosterone is metabolized to dihydrotestosterone (DHT) by 5 alpha-reductase. DHT is responsible for normal and hyperplastic growth

Question 2

How is BPH diagnosed?

Answer 2

Digital rectal exam (DRE)

Prostate specific antigen (PSA) and urinalysis (to rule out other conditions)

Question 3

Drugs that can worsen BPH

Answer 3

Centrally-acting anticholinergics (benztropine)
Anticholinergics: antihistamines (diphenhydramine), decongestants (pseudoephedrine), phenothiazines (Prochlorperazine), TCAs (amitriptyline)
Caffeine
Diuretics
SNRIs
Testosterone products

Question 4

How can BPH cause renal failure?

Answer 4

Severe blockage can cause urine to back up into kidneys

***VERY rare

Question 5

What natural products are used for BPH?

Answer 5

Saw palmetto

Unlikely to be effective

Question 6

What drug classes are used for BPH?

Answer 6

Alpha-1 blockers
5 alpha reductase inhibitor
PDE-5 inhibitor

Question 7

Alpha-1 blocker MOA

Answer 7

inhibit alpha-1 adrenergic receptors causing relaxation of smooth muscle, reducing obstruction and improves urinary flow

Question 8

When should alpha-1 blocker treatment be delayed?

Answer 8

If patient is schedule to get cataract surgery

Alpha-1 blocker causes intraoperative floppy iris syndrome (IFIS)

Question 9

What medications are non-selective alpha-1 blockers? Selective?

Answer 9

Non-selective: Doxazosin (Cardura), terazosin

Selective: Tamsulosin (Flomax)

Question 10

Alpha-1 blocker warnings, SE, and notes

Answer 10

Warnings: orthostatic hypoension/syncope esp if dose increased too quickly
SE: dizziness, fatigue, HA, abnormal ejaculation
Notes: give non-selective at bedtime to minimize hypotension; do NOT shrink prostate or decrease PSA level

Question 11

What medications are 5-alpha reductase inhibitors?

Answer 11

Finasteride (Proscar)

Dutasteride

Question 12

5-alpha reductase inhibitor CI, SE, notes

Answer 12

CI: women of child-bearing potential, pregnancy
SE: impotence, increased libido, ejaculation disturbances, breast enlargement and tenderness
6 months before max efficacy
Shrink prostate and decrease PSA levels

Question 13

5-alpha reductase inhibitor MOA

Answer 13

Inhibit 5-alpha reductase enzyme, blocking conversion of testosterone to dihydrotestosterone (DHT)

Question 14

Which PDE-5 inhibitor is indicated for BPH?

Answer 14

Tadalafil

***Do NOT use with alpha-blockers d/t hypotension