You may be surprised to learn that the medication sildenafil — better known by its brand name Viagra — has other medical purposes aside from treating male erectile dysfunction. It can also be used to treat lung diseases that often have poor prognoses.
Sildenafil works by inhibiting an enzyme called phosphodiesterase. Through a complex pathway involving other molecules, sildenafil ultimately helps smooth muscles relax and blood vessels dilate. The latter effect is known as vasodilation. Vasodilation results in more blood flow to organs — whether that organ is the penis or the lungs.
