What are PDE5 inhibitors for treatment of erectile dysfunction (ED)?

Marc B. Garnick, MD
Hematology & Oncology
PDE5 inhibitors -- sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra) -- are pills used to treat erectile dysfunction (ED). They increase blood flow to the penis by augmenting cyclic guanosine monophosphate (GMP), a chemical that relaxes muscles in the penis, improving blood flow during sexual stimulation.

All three drugs have similar effectiveness (about 60% to 70%), but tadalafil lasts about 36 hours, whereas sildenafil and vardenafil last about eight hours.

Continue Learning about Erectile Dysfunction Treatment

How effective are PDE-5 inhibitors?
Donna Hill Howes, RNDonna Hill Howes, RN
An analysis of 82 studies found that PDE-5 inhibitors were effective in 20% to 47% of men. Effective...
More Answers
Can I take an erectile dysfunction drug if I take a blood thinner?
Stacy Wiegman, PharmDStacy Wiegman, PharmD
Most men can safely take blood thinners such as warfarin (Coumadin) and enoxaparin (Lovenox) wit...
More Answers
Can Exercise Help Prevent Erectile Dysfunction?
Can Exercise Help Prevent Erectile Dysfunction?
Are Any New Drugs for Erectile Dysfunction Coming Soon?
Are Any New Drugs for Erectile Dysfunction Coming Soon?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.