People with osteoporosis have bones that become less dense and are more likely to break. The breaks most often occur at the hip, spine, and wrist. Risk factors for osteoporosis include older age, white or Asian ethnicity, and smoking. Drugs that slow bone breakdown or stimulate bone buildup are used for treatment. Such drugs include alendronate, ibandronate, and risedronate. Drugs that stimulate bone buildup are relatively new, and they include 2 manufactured forms of a natural hormone known as parathyroid hormone (PTH).