Table 1.

Proposed mechanisms contributing to AED induced bone disease.

• Vitamin D Inactivation

• Hepatic enzyme induction

• PXR activation

• Altered calcium metabolism (DPH)

• ↓ Intestinal absorption

• ↓ vitamin D mediated absorption

• ↓ intestinal cation transport

• ↑ PTH

• Vitamin D insufficiency

• ↓ cellular response to PTH

• Vitamin K deficiency

• ↓ Calcitonin

• Osteoblast Inhibition

• Altered sex-steroid & SHBG metabolism

• Possible modulation of Aromatase activity

Abbreviations: PXR: Pregnane X receptor, DPH: phentyoin, PTH: parathyroid hormone, SHBG: sex hormone binding globulin