drugs for male GU disorders

Question 1

guy has a bunch of stuff going on.

What is the most likely cause of his Erectile Dysfunction?

Atherosclerosis 
Hypogonadism
Performance anxiety
Prolactinoma 
Ramipril

Answer 1

atherosclerosis is the most common cause

Question 2

Causes of erectlie dysfunction

Answer 2

vascular (e.g. atherosclerosis)
neurologic
endocrine - *diabetes, hypogonadism, prolactinomas, hyper and hypo-thyroidism
iatrogenic
psychogenic

Question 3

Common drug-induced alterations in sexual response (stuff in red)

Answer 3

SSRIs nonselective beta blockers (100% at high doses)
phenothiazines
alcohol

Question 4

Which is the most likely target of the drug prescribed to treat pt’s ED?

5-alpha reductase 
Alpha-1 adrenergic receptor
HMG-CoA reductase
Phosphodiesterase 5
Prostaglandin E1 receptor

Answer 4

phospohdiesterase 5

Question 5

What is the mechanism of action of Viagra-like drugs?

Answer 5

key player is NO

activated myosin light-chain kinase,
guanylyl cyclase
phosphodiesterase
eNOS

Question 6

PDE-5 inhibitors

Answer 6

sildanafil (viagra)
tadalafil (cialis)
vardenafil (levitra)
avanafil (stendra)

Question 7

PDE-5 inhibitors- comparison of different agents

Answer 7

effectiveness- no acceptable evidence comparing
efficacy- varies with etiology; in general all effective in 60-70%
- no value in men who suffer loss of potency due to cord injury or damage to innervation and in men lacking libido

pharmacokinetics- 15% oral bioavailability for vardenafil to 40% for sildenafil
high fat meals delay absorption of V and s, but not tadalafil

All have similar onset: take 30 min before sexual activity (tadalafil and avanafil)
take 1 hour before sex (sildenafil and vardenafil)

the SIL-VAR HOUR

DURATION: tadalafil 36 hrs, others 4 hrs
tadalafil is available “DAILY USE”

Question 8

common adverse effects of PDE-5 inhibitors

Answer 8

flushing, headache, dyspepsia

can potentiate hypotensionesp. with alpha blocker

** contraindicated with nitrates

(CYP450 metabolism)

Question 9

additional drugs for erectile dysfunction- alprostadil

Answer 9

injected along penile shaft

PGE1 analog
used for those who do not respond to PDE-5 inhibitors. Major adverse effect is penile pain

Question 10

Which BPH agent will most likely cause orthostatic hypotension?

Finasteride
Flutamide 
Prazosin
Spironolactone
Tamsulosin

Answer 10

prazosin (alpha blocker)

Question 11

BPH drug that also treats male pattern baldness. What’s the target? and common side effects?

Answer 11

5-alpha reductase
(finasteride)

impotence, decreased libido

Question 12

what drug worsens BPH symptoms?

Answer 12

oxybutinin

used to treat bladder problems

Question 13

common adverse effect of alpha-1 adrenergic receptor antagonists

Answer 13

orthostatic hypotension and dizziness

Question 14

tamsulosin

Answer 14

highly selective for prostatic tissue; much less effect on vascular tone than other agents and does not cause hypotension

Question 15

drugs for urinary incontinence

Answer 15

mAChR antagonists
Oxybutynin, trospium, darifenacin, solifenacin, festerodine, tolterodine

adverse effects: dry mouth, dizziness, constipation, blurred vision, dry eyes, urinary tract infections

increased selectivity for m3 (solifenacin, darifenacin) decreases incidence of adverse effects

think M3 Soli-Dari-ty

Question 16

Which of the following phrases best summarizes the mechanism by which finasteride caused symptom relief?

Blocks α-adrenergic receptors	 
Blocks testosterone receptors
Inhibits dihydrotestosterone synthesis
Inhibits testosterone synthesis
Lowers plasma testosterone levels by increasing its renal clearance

Answer 16

inhibits dihydrotestosterone synthesis