The current issue of the Annals of Internal Medicine published a clinical practice guideline from the American College of Physician on drug treatment for low bone density. It contains a valuable review of the known benefits and risks of the medications used for osteoporosis which I summarize below.
This family of medicines includes Fosamax, Didronel, Boniva and Actonel. Fosamax, Didronel, Boniva and Actonel have been proven to prevent vertebral fractures, and Fosamax and Actonel have been proven to prevent hip fractures. Boniva has not been shown to prevent non-vertebral fractures. The most common side effects of bisphosphonates are gastrointestinal: acid reflux, esophageal irritation, and nausea. Bisphosphonates have also been linked to destruction of the jaw bone, a very rare but more serious side effect.
Calcitonin nasal spray has been shown to prevent vertebral fractures though the evidence is less strong than for bisphosphonates. Calcitonin does not prevent non-vertebral fractures. It has no serious side effects.
There is strong evidence that estrogen prevents vertebral and non-vertebral (including hip) fractures. But there’s also good evidence that estrogen increases the risk of blood clots and stroke. In combination with progestin, estrogen also increases the risk of breast cancer. Without progestin it increases the risk of uterine cancer.
Forteo is a relatively new treatment for osteoporosis. It is taken as a daily subcutaneous injection, making it less convenient than oral medications. It has been shown to prevent vertebral fractures, but its effect on non-vertebral fractures isn’t clear. It has no serious side effects.
Selective Estrogen Receptor Modulators (SERMs)
The two available SERMs are Evista and tamoxifen. Tamoxifen is not useful for fracture prevention and is not used to treat osteoporosis. Evista has been shown to prevent vertebral but not non-vertebral fractures. Evista increases the risk of blood clots.
Calcium and Vitamin D
The evidence on calcium and vitamin D for fracture prevention is mixed, with the most positive studies showing modest benefit. Calcium and vitamin D have no serious side effects.
Summaries for Patients: Drug Treatment for Low Bone Density or Osteoporosis to Prevent Fractures
American College of Physicians clinical practice guidelines: Pharmacologic Treatment of Low Bone Density or Osteoporosis to Prevent Fractures