Erectile Dysfunction

Question 0

Levitra, Staxyn (ODT)

Answer 0

Vardenafil
Onset of action: 30-60 minutes take on an empty stomach
DOA: up to 10 hours
SEs: headache, flushing, prolonged QT interval

Question 1

Viagra

Answer 1

Sildenafil
Onset of action: 30-60min take on empty stomach
DOA: up to 12 hr
SEs: visual changes. Blue color, blurred vision.

Question 2

Cialis

Answer 2

Tadalafil
Onset of action: 60-120 minutes
DOA: Up to 36 hrs. Can be taken once daily at low doses
SEs: back pain, myalgia, pain in limbs, some headaches and little flushing

Question 3

Stendra

Answer 3

Avanafil
Onset of action: 15-30 minutes. 15 minute onset is only true for higher doses
DOA: up to 6 hours

Question 4

Alprostadil

Answer 4

PGE1 analog
Non dependent nitric oxide mechanism
Causes an erection directly
Acts independently of external stimulation.
SEs: priapism, fibrosis, pain, and if it gets into systemic circulation; non-penile vasodilation(HA, dizziness, hypotension, tachycardia)

Question 5

Phentolamine

Answer 5

Alpha adrenergic antagonist
Non nitric oxide dependent mechanism
Blocks some of the feedback that produces nitric oxide. Injected locally, not enough to cause an erection often used in combination
Acts independently of external stimulation.
SEs: priapism, fibrosis, pain, and if it gets into systemic circulation; non-penile vasodilation(HA, dizziness, hypotension, tachycardia)

Question 6

Papaverine

Answer 6

Non-specific PDE inhibitor
Non nitric oxide dependent mechanism
Injected and acts locally to avoid systemic side effects. Helps maintain an erection, used in combination with alprostadil (causes an erection). Never used as mono therapy
Acts independently of external stimulation.
SEs: priapism, fibrosis, pain, hepatotoxicity and if it gets into systemic circulation; non-penile vasodilation(HA, dizziness, hypotension, tachycardia)

Question 7

Intracavernosal injection

Alprostadil

Answer 7

Caverject, Edex
Does not require nitric oxide
Most effective for ED, patient specific doses
Dose adjustment not required in renal or hepatic impairment
Inject 5-10 minutes before intercourse
Priapism is most common with this drug compared to others
CI: deformities, sickle cell, multiple myeloma, thrombocytopenia

Question 8

Intraurethral insert

Answer 8

MUSE (Medicated urethral system for ejection)
Alprostadil
Dose not require NO
Inserted 5-10 minutes before intercourse
CI: deformities, sickle cell, multiple myeloma, thrombocytopenia, urethral stricture, urethritis

Question 9

PGE1 MOA

Answer 9

Acts on g-coupled protein receptors. Increasing PGE1, increases cAMP, works through 2nd messenger, PKA, to decrease intracellular calcium levels leading to vasorelaxation

Question 10

Drugs that cause ED

Answer 10

Anticholinergics: tricyclics antidepressants, antihistamines(older gens), anti-parkinsonians, phenothiazines)
SSRIs
Diuretics
Sympathetic blockers (alpha, beta, and calcium channel blockers)

Question 11

PDE5i and dose adjustments

Answer 11

May need to adjust doses for renal or hepatic impairment and CYP 3A4 inhibitors (azole and protease inhibitors: ketoconanazole…ritonavir)

Question 12

PDE5 target tissue

Answer 12

Penis

Question 13

PDE 6 target tissue

Answer 13

Retina

Question 14

PDE 1 target tissue

Answer 14

Cardiac/vascular

Question 15

PDE 11 target tissue

Answer 15

Skeletal muscle

Question 16

PDE5i that primarily causes muscle and back pain

Answer 16

Tadalafil

PDE 11

Question 17

PDE5i that is commonly associated with priapism

Answer 17

Vardenafil and sildenafil. But can be seen in all PDE5i especially at high doses

Question 18

PDE5i that is associated with QT prolongation

Answer 18

Vardenafil

Question 19

PDE 5 inhibitor least likely to lower blood pressure

Answer 19

Tadalafil