Also known as disodium etidronate, this is one of a group of substances called biphosphates used mainly to treat PAGET’S DISEASE OF BONE. The drug is given orally and, when combined with calcium carbonate (Didrone®), it is used to treat osteoporosis (see under BONE, DISORDERS OF) and to prevent bone loss in postmenopausal women, especially if hormone replacement therapy (HRT – see under MENOPAUSE) is not appropriate.