Treatment of anticonvulsant drug-induced bone disease.

Although the pathophysiology of bone disease in patients treated with anticonvulsant drugs may vary, most affected patients have increased bone remodeling rather than decreased mineralization. Milder cases may show high bone turnover without significant loss of cortical or trabecular bone. Cases of intermediate severity may exhibit the characteristic features of a high-turnover osteopenia/osteoporosis, but some patients with severe bone disease may manifest the features of an osteomalacic disorder. Prophylactic vitamin D supplementation at doses up to 2000 IU/day can be recommended for all patients on initiation of anticonvulsant therapy. A calcium intake of 600-1000 mg/day should also be ensured. If an osteopenic/osteoporotic disorder exists, treatment with 2000-4000 IU/day vitamin D is appropriate. Vitamin D doses of 5000-15,000 IU/day may be needed to treat osteomalacia. Conventional treatment with bisphosphonates may be needed when the response to vitamin D is inadequate. However, routine use of bisphosphonates in patients receiving long-term anticonvulsant therapy cannot at present be recommended.