Erectile Dysfunction

Question 1

Name a PDE-5 inhibitor

Answer 1

Sildenafil (Viagra)

Question 2

When are PDE-5 inhibitors contraindicated?

Answer 2

• If a patient is on nitrates or riociguat
• If vasodilation and sexual activity is not recommended
• Who have lost vision in one ye due to non arteritic anterior ischaemic optic neuritis
• Hypotension (below 90/50)
• Unstable angina/ angina occuring during sex

Question 3

What is sildenafil contraindicated?

Answer 3

• Recent history of stroke or MI
• Severe hepatic impairment
• Hereditary degenerative retinal disorders

Question 4

What are side effects of PDE-5 inhibitors?

Answer 4

Back pain
Nausea
Dyspepsia
Flushing
Migraine
Myalgia 
Nasal congestion 
Dizziness
Vomiting

Question 5

What are uncommon but serious side effects of PDE-5 inhibitors?

Answer 5

• Visual disturbaces (NAION)
• Sudden hearing loss
• Priapism
  Seek urgent medical advice and stop taking the drug

Question 6

What are interactions with PDE-5 inhibitors?

Answer 6

• Nitrates (hypotension)
• Guanylate cyclase inhibitors
• Alpha blockers (postural hypotension)
• CYP inhibitors reduce clearance of these drugs (reduce dose to 25mg)
• CYP inducers affect these drugs

Question 7

When does the patient take the PDE-5 inhibitor?

Answer 7

50mg taken one hour before sex or longer if taken with food

- Don’t take more than 100mg in one day