Recently the FLEX (Fracture Intervention Trial Long Term Extension) trial that was published in the Journal of the American Medical Association (JAMA) left us with some very interesting information. This was a randomized, double-blind trial that compared the effects of discontinuing alendronate (Fosamax) treatment after 5 years vs. continuing it for 10 years. The trial showed that women who discontinued their osteoporosis medication after 5 years had a decline in their bone mineralization (DXA scores), but yet no higher risk of non-vertebral fractures.
This news may be important for some, but not all. I have many patients who have been on Fosamax for many years and have been wondering if they could stop it for a few years. In the past, it was difficult to answer due to the lack of data. This, although with limitations, gives us some direction.
Before stopping one’s medication, one should pay close attention to whom this study seems to include.
If one is young, male, very elderly (average age in study was 73), or has severe disease (only ~30% of the study patients had osteoporosis), I would be very careful. The study did not include these groups and since we know that different ages and bone densities have extremely different risks of fractures, one should not generalize the results to all.
Another important factor to look at is the individual’s risk of vertebral fracture. In the group that stopped treatment, there was a significantly increased risk of vertebral fractures. This is very important since many people have decreased mineralization in both vertebral as well as hip regions. Before one looks at their density "numbers," they should be really careful that their vertebral region is “really normal.”
Bone density analysis of the vertebrae is often very difficult to interpret. Frequently, due to arthritis and possibly fractures, the bone mineralization appears better then it really is (artifact). If there is any suspicion that something is amiss (one vertebra on the scan is much better then the others or there are abnormalities of the pictures), one should have a lateral vertebral assessment (side DXA), x-rays, or MRI to evaluate for fractures. If this was discovered, it makes no difference what the DXA numbers show; one is still at high risk for vertebral fractures. This is because previous vertebral fracture puts one at high risk for another.
I would also be careful not to generalize these results to other bisphosphonates. Actonel and Boniva, although, in the same class and with similar bone mineral increases in their studies, are truly different drugs. This is due to their half life, the time it takes for them to leave the body.
If you seem to fit all of the above, I still wouldn’t be so quick to switch to Fosamax, from one of the other drugs. If one of these drugs is working, one takes a risk of the other drug not working or having a side effect. Also, in five years from now, the osteoporosis treatments and the way we treat the disease is sure to be very different. This is due to expected new drug approvals as well as pending information from the World Health Organization that is to give us better direction and evaluation of risk factors to guide who should be treated.