phlebotonic

Adjective

 * 1) Affecting the tone of veins; that is, affecting the muscle tone of the smooth muscle in the walls of veins, thus influencing blood flow within the lumen.

Noun

 * 1) A substance (especially a drug) that is phlebotonic; a drug that modifies the tone of vein walls to treat  causing, hemorrhoids, or varicose veins.