https://www.medzsafe.com/product/fildena/
Phosphodiesterase type 5 (PDE5) is an enzyme that is inhibited by the medication Fildena. Cyclic guanosine monophosphate (cGMP), which controls blood flow in the penis, is degraded by this enzyme. Fildena works to sustain higher amounts of cGMP by blocking PDE5, which improves blood flow and improves erectile function.