Erectile dysfunction

Question 1

Describe the process by which NO is made and works

Answer 1

In endothelial cells

L-arginine converts into NO by NOS (synthase) - causes relaxation in vessels

Question 2

What does NO do in the penis?

Answer 2

Vasodilation of arteriole side = inc blood flow in = erection

Question 3

NO is released as a neurotransmitter in the penis T/F?

Answer 3

TRUE

Question 4

What molecule besides NO is involved in vasodilation in the penis?

Answer 4

cGMP

Question 5

Go through structure of the penis

Answer 5

corpus cavernosum and corpus spongiosum

no tunica vaginalis

Question 6

What triggers NO-mediate vasodilation?

Answer 6

parasympathetic innervation

Question 7

What enzyme breaks down cGMP? What’s the effect of this?

Answer 7

PDEV - phosphodiesterase V

inactivation

Question 8

What’s the name of the drug that can inhibit the enzyme^?

PDEV

Answer 8

slidenafil

Question 9

What are the 2 alternative drugs to stimulate erection?

Answer 9

alpha-blocker:
phenoxybenzamine
papaverine

both block SNS

Question 10

What’s one key drug interaction for sildenafil?

Answer 10

nitrates - can cause hypotension

Question 11

What’s the tmax and t1/2 of sildenafil? How would you counsel the patient?

Answer 11

tmax = 1 hr
t1/2 = 3.5 hrs 

to take 1 hr before sexual activity
dont take more than 1 per day

Question 12

What are some causes of ED?

Answer 12

CVD
smoking
diabetes
psychogenic
drugs: thiazides, prazosin, antidepressants, antipsychotics