Treating Osteoporosis:
Medications That Can Increase Bone Density and Decrease Bone Fractures
Estrogen therapy can prevent or stabilize the process of osteoporosis and is approved by the FDA for the prevention of osteoporosis, relief of vasomotor symptoms (hot flashes), and vaginal atrophy/dryness associated with menopause. The Women’s Health Initiative (WHI) clinical trials found that 5 years of hormone therapy (Prempro was studied) reduced the risk of clinical vertebral fractures and hip fractures. However, when the use of hormone therapy is considered solely for prevention of osteoporosis, approved non-estrogen treatments should be considered first, according to WHI recommendations. The risks of hormone therapy may outweigh the benefits. The decision should be made between the physician and patient after carefully reviewing treatment goals, risks and benefits. The FDA recommends that if estrogen is prescribed, it should be at the lowest dose for the shortest period of time to manage symptoms of menopause. The FDA also wants doctors to discuss alternative osteoporosis medications for women at risk for or diagnosed with osteoporosis.
Raloxifene (Evista)®, an estrogen-like medication, is approved by the FDA for both prevention and treatment of osteoporosis in postmenopausal women. Raloxifene increases bone mass in the vertebrae modestly and reduces risk of vertebral fracture.
While side effects are not common, risk of deep vein thrombosis is increased similar to that observed with estrogen. Hot flashes can be a side effect. Raloxifene has no action on breast or uterine tissue. It is currently under study to see if it reduces the risk of estrogen-dependent breast cancer. Raloxifene appears to decrease the risk of setrogen-dependent breast cancer by 65% over four years according to the National Osteoporosis Foundation.
Bisphosphonates:
Alendronate (Fosamax) is a bisphosphonate approved by the FDA for the prevention (5 mg daily and 35 mg weekly) and treatment (10 mg daily and 70 mg weekly) of osteoporosis in postmenopausal women. It reduces bone loss and increases bone density.
Risedronate (Actonel) (5 mg daily does and 35 mg weekly) is a bisphosphonate approved by the FDA for the prevention and treatment of postmenopausal osteoporosis. It reduces bone loss and increases bone density.
Clinical trials have found the incidence of side effects in patients taking alendronate and risedronate to be low, but some patients may experience upper gastrointestinal disorders. Alendronate and risedronate must be taken after a prolonged fast with 8 ounces of water (no other liquid), at least 30 minutes before eating or drinking. Patients must remain upright (sitting or standing) for this time period as well. The option for once a week dosing has made this regimen less troublesome for many patients.
Calcitonin (Miacalcin)® is a naturally occurring hormone involved in calcium regulation. It is FDA-approved for the treatment of osteoporosis in women who are a minimum of 5 years postmenopausal. It is self-administered via nasal spray but subcutaneous injection is available also. Studies show that calcitonin decreases vertebral fracture risk but did not alter non-vertebral fracture rate in those studies. Calcitonin is generally well-tolerated and may reduce back pain from vertebral compression fractures.
Parathyroid hormone (Forteo)® is one of the newest treatments approved by the FDA for the treatment of osteoporosis in postmenopausal women and in men. It is a bone-building agent when given in daily subcutaneous injections. It has been well tolerated although some patients experience leg cramps and dizziness. Vertebral and non-vertebral fracture risks were reduced by 65% and 54% respectively over 18 months of therapy. However, the safety and efficacy of PTH has not been demonstrated beyond 2 years of treatment. Physicians are likely to choose another medication for treatment that is easier to administer and has safety and efficacy documented for a longer time period.
Non-FDA Approved Drugs
The FDA has not yet approved the following drugs for the prevention or treatment of osteoporosis. It is possible that the manufacturers will seek FDA approval for use in osteoporosis patients in the future. They are listed for information only.
Calcitriol: a synthetic Vitamin D preparation that promotes calcium absorption.
Other bisphosphonates: etidronate, ibandronate, pamidronate, tiludronate, and zoledronic acid: These vary chemically from alendronate and risedronate but are in the same drug class. Most are approved for other conditions, not osteoporosis. Ibandronate and zoledronic acid are under evaluation as treatment for osteoporosis.
Sodium fluoride: This stimulates formation of new bone. But the quality of bone mass is uncertain as is the evidence if it reduces fracture risk.
Tibolone: This is indicated in Europe for treatment of hot flashes and for prevention of osteoporosis, but is not yet approved in the US. It is an estrogen-like agent but does not stimulate breast or uterine tissue.
