Chapter 117 discusses common medication-induced changes of the musculoskeletal system. The effect of corticosteroids on the musculoskeletal system, including osteoporosis and osteonecrosis, is discussed. Corticosteroids decrease osteoblastic activity, stimulate bone resorption, and decrease intestinal absorption of calcium. Complications of bisphosphonate therapy such as atypical femoral fractures and osteonecrosis of the jaw are reviewed. Myopathies and tendon pathologies are briefly discussed, as well as bony changes potentially seen with long-term voriconazole treatment. For osteoporosis, DXA scan is the gold standard, whereas radiography is usually the first imaging modality performed in patients on voriconazole therapy who present with pain.