Doxazosin Doxazosin tablets What do doxazosin tablets do?DOXAZOSIN (Cardura(R)) is an antihypertensive. Doxazosin lowers, but does not cure, high blood pressure. It works by relaxing your blood vessels. It also can be used to treat enlargement of the prostate gland in men. Generic doxazosin tablets are available.