Phosphodiesterase inhibitors

Question 1

What is an example of a phosphodiesterase inhibitor?

Answer 1

Sildenafil

Question 2

What are indications for phosphodiesterase inhibitor use?

Answer 2

• ED
• Primary Pulmonary hypertension

Question 3

What is the mechanism of action of phosphodiesterase inhibitors?

Answer 3

Selective for PDE type-5 that is found predominantly in the smooth muscle of the corpus cavernosum of the penis and arteries of the lung

Question 4

How does phosphodiesterase receptor inhibition result in blood flow into the penis?

Answer 4

PDE is responsible for the breakdown of cGMP, which is responsible for causing arterial smooth muscle relaxation, vasodilatation and penile engorgment. Inhibition of this enzyme increases the levels of cGMP, which increases blood flow and erection quality

Question 5

What are adverse side effects of phosphodiesterase inhibitors?

Answer 5

• Flushing
• Headache
• Dizziness
• Nasal congestion
• Hypotension
• Tachycardia
• Palpitations
• Vascular events
• Priapism
• Visual disorders

Question 6

When should phosphodiesterase inhibitors not be used?

Answer 6

• Stroke
• ACS
• CVD

Question 7

What should you not prescribe phosphodiesterase inhibitors with??

Answer 7

• Nitrates
• Nicorandil