Medications for osteoporosis
Estrogen replacement therapy
Estrogen replacement therapy has been shown to significantly decrease the risk
of fractures. After the onset of menopause, women are encouraged to speak with
their doctor about taking estrogen replacement. Women with contra-indications,
such as breast cancer, clotting disorders or a history of pulmonary embolism,
are typically not considered candidates for estrogen replacement.
Estrogen therapy for longer than 6 years has been shown to provide approximately
50% reduction in osteoporotic fractures. If estrogen therapy is started by
the age of 70, there is a 30% decrease in the risk of hip fractures and a 36%
decrease in associated mortality.
Estrogen is also thought to have additional positive side effects, such as:
- There is a probable decreased risk of colon cancer
- There is a probable 50% decreased risk of coronary heart disease
- Improved sleep
- Improved memory
- Increased muscle mass
- Fewer urinary tract infections
- Improved libido
Approximately 8 to 9% of women taking estrogen replacement therapy do have
increased bone loss. For these women, and for women not taking estrogen replacement,
there are alternative treatments including the use of anti-resportive therapies
(such as Alendronate and Calcitonin).
Alendronate
The use of Alendronate (e.g. Fosamax) causes a shift of bone balance toward
bone formation and has been shown to increase bone mass. Alendronate is significantly
more expensive than estrogen, but its ability to prevent fractures is very
similar to estrogen.
Two studies about Alendronate include:
- Lieberman et al — 10 mgs of Alendronate per day over a three-year
period of time built bone mass in 96% of patients and decreased the risk
of fracture significantly.
- Fracture Interventional Trial by Black et al — with the use
of Alendronate, there was a 47% decrease in new vertebral fractures, a 50%
decrease in hip fractures, a 55% decrease in the risk of symptomatic vertebral
fractures, a 48% decrease in wrist fractures, and a 28% decrease in the risk
of all clinical fractures.
Calcitonin
Calcitonin(e.g. Miacalcin) is a hormone that is produced naturally
in our bodies, and it is is now available as a prescription medication. It
can be taken in injection form or intranasal (through a nose spray). This has
been found to increase bone density mainly in the spine.
Calcitonin is indicated for patients who are approximately 5 years past menopause
and have low bone mass, or with obvious osteoporosis, who choose not to or
cannot take estrogen. Calcitonin has also been shown to be helpful for pain
management with compression fractures. The effectiveness of Calcitonin tends
to plateau approximately 18 years after menopause.
In the study of anti-resorptive agents over a two-year period, there was a
comparison of placebo, estrogen, calcitonin and alendronate. Increases in bone
density were noted with all agents, as follows:
- Estrogen — 5%
- Alendronate — 8%
- Calcitonin — 2%
There was no residual protection from bone loss after stopping the estrogen
and calcitonin, however, after stopping the Alendronate a positive bone balance
was noted.
By: Donald J. Frisco, MD
November 1999
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