Anticonvulsants osteoporosis with

Primary osteoporosis is the most common form of the condition. The secondary form of osteoporosis is diagnosed when an illness and/or medications are present with a negative impact on BMD. Examples of common chronic conditions in old people that can cause secondary osteoporosis are seen in Box 5.14. Examples of drugs that can cause secondary osteoporosis are glucocorticoids, too high doses of thyroid hormone, anticonvulsants, and heparin. Especially the use of glucocorticoids has been known to cause severe osteoporosis even within a short period of treatment. Depending on the doses the development of osteoporosis can occur within a few weeks or months. 

Spontaneous reports of osteoporosis, osteopenia, bone fractures, and delayed healing of bone fractures have been seen in the isotretinoin population. While causality to isotretinoin has not been established, an effect cannot be ruled out. Physicians should use caution when prescribing isotretinoin to patients with a genetic predisposition for age-related osteoporosis, a history of childhood osteoporosis conditions, osteomalacia, or other disorders of bone metabolism. This would include patients diagnosed with anorexia nervosa and those who are on chronic drug therapy that causes drug-induced osteoporosis/osteomalacia and/or affects vitamin D metabolism, such as systemic corticosteroids and any anticonvulsants. 

Certaiu medicatious have beeu associated with au iucrease iu osteoporosis risk, particularly steroids and anticonvulsants. Steroid-induced osteoporosis arises due to use of glucocorticoids, analogous to Cushing s syndrome, and involving mainly the axial skeleton prednisone... 

Epilepsy and osteoporosis are very common and frequently overlap. Nevertheless, the prevalence of low bone density appears to be disproportionately higher in patients with epilepsy, and patients with epilepsy have an excessive risk of fractures. A meta-analysis of 94 cohort studies and 72 case-control studies has shown that anticonvulsant treatment is highly associated with fractures (relative risk over 2) (117). Other risk factors were low body weight, weight loss, physical inactivity, consumption of corticosteroids, primary hjrperparathjroidism, type 1 diabetes melhtus, anorexia nervosa, gastrectomy, pernicious anemia, and age over 70 years. 

Drugs have also been associated with osteomalacia. Anticonvulsants increase the hepatic cataboHsm of vitamin D metabolites, and produce end-organ resistance. Phosphatebinding antacids used for treatment of peptic ulcer disease cause osteomalacia by preventing the intestinal absorption of phosphate. Etidronate treatment (e.g., of Paget s disease, osteoporosis, or hypercalcemia of mafignancy) can cause a mineralization defect and result in osteomalacia. 

---