Treating Osteoporosis: What Works Best?
Parathyroid Hormone and Fosamax Studied in Women With Advanced Osteoporosis
Aug. 10, 2005 -- When bones get dangerously thin with advanced osteoporosis, what drugs help build those bones back up?
Two osteoporosis treatments -- parathyroid hormone and Fosamax -- are the topic of two small studies in The New England Journal of Medicine.
- Treatment with parathyroid hormone increases bone density. But women who took parathyroid hormone for a year progressively lost bone density afterward unless they took Fosamax (compared with placebo).
- Women got the same bone-building benefits -- for less money and effort -- by taking parathyroid hormone on three-month on-again, off-again cycles, compared with daily use.
Bones change all the time on the inside. They're constantly remodeling themselves, like a home improvement crew that just can't quit.
Early in life, new bone is built faster than old bone is torn down. Around age 30, the wrecking crew starts to outpace the bone-building team.
That's a natural part of aging. But matters worsen if bones were weak to begin with. A shortage of building supplies (calcium, vitamin D, and certain minerals) and lack of incentive (weight-bearing exercise) sours the situation even more.
Then there are the calcium raiders. Other parts of the body need calcium, and they leach it out of bones if they can't get it any other way -- for example, from dairy products, leafy green veggies, and calcium-fortified foods. Some medicines, smoking, and too much alcohol can also wear down bone.
Add it all up, and both men and women can get osteoporosis. Their bones look more like lace than concrete or steel. Fragile bones are more likely to break, which can make seniors more isolated and less independent.
How the Drugs Work
Fosamax and parathyroid hormone both seek to strengthen bones, but they work differently.
Fosamax orders the bone-breakdown crew to take it easy. Parathyroid hormone tells the bone builders to pick up their pace. Parathyroid hormone is used for severe osteoporosis cases, and it's only approved for up to two years of treatment.
One of the new studies included 126 women with osteoporosis. After taking Fosamax for at least one year, they added parathyroid hormone to their treatment, or the women continued treatment with Fosamax.
Half of the women who used parathyroid hormone shots used it daily. The others gave themselves daily shots for three months, followed by a three-month break, and so on, for 15 months.
The on-again, off-again cycle was as effective as the daily shots at building bone at the spine, with fewer costs and effort for patients, write the researchers. They included Felicia Cosman, MD, of the Clinical Research Center at Helen Hayes Hospital in West Haverstraw, N.Y.