Hydrazinophthalazine

Hydrazinophthalazines are a class of antihypertensive drugs including:


 * Hydralazine
 * Dihydralazine
 * Cadralazine
 * Endralazine

Chemically, the latter two aren't phthalazines; but they are classified as such in the World Health Organization's Anatomical Therapeutic Chemical Classification System.