Bidil is a combination drug of hydralazine and Isosorbide dinitrate. Hydralazine serves as a vasodilator. The drug relaxes both arteries and veins in order to make it easy for the heart to work normally, in pumping the blood to the other parts of the body. The component, Isosorbide dinitrate acts on the blood vessels by dilating them. When dilation takes place, it becomes easy for the heart to perform its functions. This allows more blood rich in oxygen to freely flow to the heart. This medication is meant specifically for African-Americans suffering from heart disease.