QUESTION: Recently I read about the new drug etidronate which is supposedly a real break through in treating osteoporosis with very minimal side effects. Our doctor seems to know nothing of this drug, but our pharmacist says with a prescription he can order it and have it in the next day.
Could you please advise if and when this drug was approved by the Food and Drug Administration (FDA), and when it will be on the market? I am sure many people are eager to learn more about this important drug.
ANSWER: Your letter brings up some important points that have been included in recent mail from other readers and so I am pleased to respond.
The articles you have been reading about etidronate followed the publication of two reports about new research using this medication presented in the New England Journal of Medicine in May and July of this year.
One study was conducted in Denmark, involved 66 patients and covered a three year period.
A much larger study involved 429 women with postmenopausal osteoporosis was conducted over a two year period in centers in Cincinnati, Cleveland, Atlanta, Seattle, Honolulu, Denver and Columbus, Ohio.
A method called "intermittent cyclic therapy" (ICT) was used in both studies.
Contrary to the thinking of many people, bone is not a dead tissue, but a dynamic one, constantly being torn down and rebuilt by special cells.
The osteoclasts are responsible for tearing down old bone, with the osteoblasts working to rebuild the bone and form new bony structures.
During most of our adult life these two processes are pretty much in balance, but after menopause, the osteoclasts get the upper hand, with more destruction of bone than new building.
The result is a thinner or more porous bone, thus the name osteoporosis.
In these experiments etidronate was given to slow down the osteoclastic activity for a period of time (15 days), and then stopped, permitting the osteoblasts to function and rebuild bone.
During the bone rebuilding portion of the cycle, calcium supplements were given to help the process.
The entire cycle spanned a three month period and then was repeated.
Both groups of researchers reported that bone mass improved (as measured by bone density techniques) during the therapy, and more important still, that the number of vertebral fractures (the type that cause the formation of a "dowager's hump" or spinal curvature) was significantly reduced in the group receiving etidronate when compared to the control group.
Etidronate is not unknown to doctors practicing in the United States.
It is currently marketed under the name Didronel by Norwich Eaton, and is already approved for use in treating Paget's Disease of the bone, and is considered safe and effective for this indication by the FDA.
However, when a medication that has been approved for one indication is found useful for a new disease or indication, the manufacturer must submit evidence and scientific data to the FDA to prove that it is an effective treatment for the new disorder as well.
The news is that the manufacturer has submitted the results of these two studies as well as other supportive data to the FDA at this time and is awaiting its decision.
Just how long the process will take is unknown, but I will be happy to let you know when it occurs.
So your pharmacist is correct, he can order the medication now, but I would strongly advise your physician to read these two articles before deciding to issue a prescription, because the medication must be taken in a very precise manner to obtain the same results as these investigations.
The material contained here is "FOR INFORMATION ONLY" and should not replace the counsel and advice of your personal physician.
Promptly consulting your doctor is the best path to a quick and successful resolution of any medical problem.
