Isoxsuprine is in a class of drugs called vasodilators Isoxsuprine relaxes veins and arteries  which makes them wider and allows blood to pass through them more easilyThese actions may help treat the symptoms of conditions such as cerebral vascular insufficiency - poor blood flow to the brain -  arteriosclerosis - hardening of the arteries -  Raynaud's phenomenon  and other conditions involving poor blood flow in the veins and arteries