Phosphodiesterase 5 (PDE5) inhibitors

Definition

Phosphodiesterase 5 (PDE5) inhibitors are a class of drugs that block the enzyme PDE5, leading to increased blood flow in certain tissues. They are commonly used to treat erectile dysfunction and pulmonary arterial hypertension.

5 Must Know Facts For Your Next Test

1. PDE5 inhibitors include sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra).
2. They work by preventing the breakdown of cyclic guanosine monophosphate (cGMP), which enhances blood flow.
3. Common side effects include headache, flushing, and dyspepsia.
4. PDE5 inhibitors should not be used with nitrates due to the risk of severe hypotension.
5. These drugs can also be used off-label for other conditions like Raynaud's phenomenon.

Review Questions

• What is the primary mechanism of action for PDE5 inhibitors?
• Name three common PDE5 inhibitors used in clinical practice.
• Why should PDE5 inhibitors not be taken with nitrates?

Related terms

Sildenafil: A PDE5 inhibitor commonly known as Viagra, used primarily to treat erectile dysfunction.

cGMP: Cyclic guanosine monophosphate, a molecule that helps regulate blood flow and is affected by PDE5 inhibitors.

Nitrates: A class of drugs often prescribed for chest pain that can dangerously interact with PDE5 inhibitors.