Phosphodiesterase-4 Inhibitors

Phosphodiesterase-4 is an enzyme that degrades cAMP.  By inhibiting phosphodiesterase 4, these medications increase cAMP levels.  cAMP activates PKA, which in turn activates anti-inflammatory cytokines.  Reduction in inflammation of the airways reduces risk of exacerbation of COPD in patients with severe COPD.  These medications can cause headaches, nausea, vomiting, and diarrhea.  

Class Drugs

• Roflumilast

Class Mechanism of Action

Inhibits phosphodiesterase 4 enzyme

• Anti-inflammatory: increases levels of intracellular cAMP in lungs resulting in increased production of anti-inflammatory cytokines.

Class Applications

COPD

• Not a rescue drug

• Needs to be dosed frequently due to short half-life, limits adherence

Class Adverse Effects

Nausea, Vomiting, and diarrhea

Headache

Drug Table

Drug Name	Application	Comments	Image
Roflumilast			"Roof" "Loom" "Last"