PHRM 825 Lecture 50- Mens Health Part 3

persistent inability to achieve and maintain penile erection sufficient for satisfactory sexual performance

erectile dysfunction

what is the #1 risk factor for ED

age

diseases and conditions that can contribute to ED

diabetes, HTN, CAD, Parkinson's, stroke, low testosterone levels (rarely)

physical factors that can lead to ED

injury, surgeries, medicines, radiation

which drug class is most often associated with male sexual dysfunction

antidepressants (SSRIs)

which drugs can lead to sexual dysfunction

antidepressants, antihypertensive agents, estrogens/ antiandrogens, 5-a reductase inhibitors, cancer chemotherapy

lifestyle choices that can lead to ED

excessive alcohol, tobacco smoking, obesity, inadequate sleep, stress

three subtypes of erections

psychogenic

reflexogenic

nocturnal

which division of the ANS initiates erections

parasympathetic

which neurotransmitter is released upon sexual stimulation and what does it cause the release of

ACH is released and causes release of nitric oxide

what does NO activate and what is converted

NO activates guanylate cyclase which converts GTP to cGMP

what does elevated levels of cGMP cause

Ca release, producing smooth muscle relaxation in the penis

step 1 treatment of ED

treat or eliminate known causes (discontinue or change drugs if drug induced)

testosterone treatment if hypogonadism present

step 2 treatment of ED

oral PDE 5 inhibitor or vacuum erection device

step 3 treatment of ED

intraurethral or intracavernous Tx

step 4 treatment of ED

possible combination therapy

step 5 treatment of ED

penile prosthesis

first line treatment choice for most patients

oral therapies

MOA of oral therapies

promotes smooth muscle relaxation in the penis by inhibition of PDE 5

sexual stimulation required

what are the PDE5 inhibitors

Sildenafil

Vardenafil

Tadalafil

Avanafil

Viagra, generic

sildenafil

Levitra

vardenafil

Cialis

Generic

Tadalafil

Stendra

Avanafil

what to do if man does not respond to initial oral dose

try a larger dose

adjust dose to produce an erection that lasts no longer than 1 hour

drug interactions of PDE5 inhibitors

CYP3A4 inhibitors- cimetidine, ketoconazole, erthromycin, ritonavir, grapefruit juice

prolongs effect of drug

use 25 mg instead of 50 mg starting dose of Sildenafil IF:

>65 years old

hepatic impairment

CrCl <30

what delays absorption of PDE5 inhibitors

food

side effects of PDE5 inhibitors

headache, flushing, NAION (sudden vision loss)

precautions of taking PDE5 inhibitors

patients on oral or transdermal nitrates

patients on alpha blockers (start lower dose)

patients with very severe CAD

erections that last longer than 4 hours

what drugs are in the compounded sublingual tablet for ED

sildenafil 55mg + tadalafil 22 mg

very effective for ED

slow onset

base ring used to maintain erection

$300-$500

vacuum erection devices

causes erection to happen instead of maintaining erection

transurethral therapy

transurethral suppositories

less effective than injection

onset within 5-10 minutes

alprostadil pellets (MUSE)

used if patient fails PDE5 inhibitor

best for neurogenic ED

onset within 5 min, lasts 1 hour

highly effective

intracavernosal injection

Alprostadil injection (Caverject)

dosing of alprostadil injection

start at 2.5 mcg- 10 mcg

usual range is 10-20 mcg

titrate dose to produce 1 hour erection

3 drugs in Trimix injection

Papaverine

Phentolamine

Prostaglandin E1

semi-rigid insert

irreversible pump only used when other treatments fail

penile prostheses

condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended

priapism

causes of priapism

drugs

sickle cell disease

pelvic tumors and infections

drug induced priapism

ED drugs

antidepressants

antipsychotics

anticoagulants

cocaine

treatment of priapism

phenylephrine

blood aspiration

saline irrigation