Wednesday, November 7, 2012

Osteoporosis Drug Risks


Osteoporosis Drug Risks

There has been a lot of recent concern recently about osteoporosis drug risks.
Osteoporosis is a condition of the bones that increases the risk of fractures.

One in 2 women and one in 4 men over the age of 50 will break a bone due to osteoporosis.
About 2 million fractures related to osteoporosis occur each year in the United States.
About 300,000 are hip fractures.
Hip, wrist and vertebral (spine) fractures cause untold suffering and disability.

Guidelines and online calculators  and an app for the iphone are available to guide physicians as to who should be treated with medication. Those persons who have had a so-called fragility fracture are much more likely to have another fracture.

The most commonly used drugs to treat or prevent osteoporosis are called bisphosphonates. The four bisphosphonates used for osteoporosis in the U.S are alendronate, ibandronate, risedronate, and zoledronic acid.
The brand names for these are Fosamax, Boniva, Actonel and Reclast.

Reclast is given once a year intravenously. Boniva is available by mouth given monthly and intravenously once every 3 months . Fosamax and Actonel are given by mouth.

Doctors never want to cause more harm than good with a medication.
Recently, a possible increased risk of unusual fracture of the “thigh bone”, the femur, has been seen. This atypical fracture is thought to be possibly increased in those persons on long-term bisphosphonates.

In this post I will focus on these so called atypical sub-trochanteric fractures. 
Some may be concerned about osteonecrosis of the jaw (abbreviated ONJ)  with bisphosphonates. When bisphosphonates are used for osteoporosis, ONJ appears to be very rare and not clearly caused by the drug at these doses. 
A recent article discusses safety concerns of bisphosphonates.

The American Society of Bone and Mineral Research has provided a detailed report on atypical sub-trochanteric fractures. Of all hip and femur fractures, less than 1% are these atypical sub-trochanteric fractures. These atypical sub-trochanteric fractures appear more likely, perhaps two and half times more likely, in those who have taken bisphosphonates for more than 5 years.

That sounds bad but the risk of such fractures is very low.
Atypical sub-trochanteric fractures occur at a rate of about 3 in 10,000 women over 1 year  who are 65 years or older.
But typical hip fractures overall are 30 times more frequent: 103 in 10,000 women aged 65 or older over 1 year.

And bisphosphonates have repeatedly been proven to reduce fractures in those at increased risk for fracture. 
Bisphosphonates reduce fractures by 30-70% depending on the drug studied and the particular fracture.

So what should be done while we wait to learn more about these atypical sub-trochanteric fractures?

Those who really need treatment should be treated. FRAX can be very useful. But sound judgement and clinical expertise needs to be coupled with FRAX.    I often see patients who probably do not need the medication they are taking for their bones.

We should consider discontinuing treatment in those who are doing well and who are at lower risk after 5 years of oral bisphosphonates or 2-3 years of intravenous bisphosphonates. Recent data suggest that FRAX may be helpful in deciding when to stop treatment with a bisphosphonate.
At this time, there are no studies on how long treatment might be stopped.
Many people, especially those with more severe disease and history of fractures, will do best by continuing treatment.

Keep in mind that we do not have data on  atypical fractures in those treated with Prolia long term.
And Prolia is not a bisphosphonate but it appears to be highly effective.

Discuss matters with your doctor who should be keeping up to date with developments in this area.
And remember no treatment is without risk. 
We should weigh risks versus benefit. 
There may be no clear right or wrong answer here.
And if in doubt, patients and or doctors should get another opinion.
In general, endocrinologists and rheumatologists are the specialists with expertise in osteoporosis.

I hope this helps in thinking about osteoporosis drug risks versus benefits.



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