Viagra is so popular that its name has become synonymous with ED treatment — just like Ziploc has with plastic bags. But the active ingredient in Viagra is sildenafil. Pfizer Pharmaceuticals patented ...

This story was reviewed by Mike Bohl, MD. In the ‘80s, researchers set out to test a medication called sildenafil citrate for treating high blood pressure and angina (chest pain) from heart disease.

Studies focused on Asian populations with pulmonary arterial hypertension (PAH) treated with sildenafil are rare, and a new meta-analysis has found the phosphodiesterase-5 inhibitor effective in this ...