What You Need to Know If You Are Taking a Bisphosphonate

By Donald A. Bergman, MD, MACE

Why should you take a drug that may cause damage to bones of your jaw or hip? The answer is simple.

If you have osteoporosis the drug may save your life. Osteoporosis [os-tee-oh-puh-ROH-sis] causes 250,000 hip fractures per year in this country. Hip fractures can be associated with many complications, including death in the months after the fracture. The drugs called the bisphosphonates [biss-FAHS-fuh-nates] (available under the trade names Actonel, Boniva, Fosamax, and Reclast) have been shown to reduce the risk of hip fracture by close to 50%. They also reduce the risk of other fractures, including spine fractures and fractures of other bones. When taken properly the bisphosphonates are safe for most people.

Understanding Osteoporosis

“Osteoporosis is a condition in which the bones become thin and full of holes like a sponge. Why does that happen? Bones are constantly repairing themselves. Your bones are able to handle great stress, bearing up under constant stress. Every time you lift something, run, jump, or fall down your bones must be hard enough to support the load of what you are carrying, including the weight of your own body. At the same time, your bones must be flexible enough to bend slightly when you lift a heavy package. Your bones are able to do this because they are made of collagen, the same collagen that is under your skin and that holds you together. This allows your bones to be flexible. The bones also have calcium mixed in with the collagen, very much like vegetables floating in vegetable soup. The calcium crystals allow the bones to be hard so that your bones can give your muscles support and allow you to move, as well as carry and lift things. Day-to-day stress on your bones causes little cracks to occur, which must be repaired. If they weren’t repaired, the damage from the little cracks would build up, weaken the bone structure, and allow fractures to occur. But with healthy bone, small bits of bone are regularly removed and new bone is laid down. You get a whole new skeleton on average every ten years!

In the most common type of osteoporosis, the process of removing old bone and putting down new bone happens too quickly. There is not enough time to fully replace the bone that has been removed as part of the normal repair process. This results in thinner bone that becomes porous (full of holes like a sponge or swiss cheese). Also, there is no time to fully repair the normal daily damage that occurs to our bones. In osteoporosis the “holes” in the bone and the normal daily damage results in weak bones, which will break.

What the Bisphosphonates Do

The bisphosphonates slow down the bone repair cycles. This prevents further damage and porosity. Even though this does not sound like much, bisphosphonates work well, usually reducing fracture risk in the hip by close to 50% and fracture risk in the spine by more than 50%. This type of drug mostly works by keeping bone from breaking down, which is part of the problem in osteoporosis, but unfortunately it also can keep new bone from forming. This is because the two processes are connected. The breaking down of old damaged bone and the formation of new bone to replace the old are closely tied to each other like a beautiful ballet of the bones. So, when the bisphosphonates slow down bone breakdown, they also slow down bone formation, which may prevent proper healing of bone. This slowing down of bone healing seems to become more of a problem in people who use the drug for a length of time. If bone repair is slowed, then fracture – the very thing that the drug is supposed to prevent – may happen.

Solving the Problem

Both jaw damage and spontaneous hip fracture are rare and occur in people who have never taken this type of drug. Jaw damage may be due to the drug slowing down bone repair along with poor blood supply to the jaw in people with other diseases, but this is not certain. Spontaneous hip fracture may be related to how many years you take the drug. No studies have looked specifically at these complications and how to prevent them, so the suggestions given here are based on opinion rather than evidence.

If spontaneous hip fracture is related to how long you’ve taken the drug, then it makes sense to get off the drug now and then (a “drug holiday”). Exactly when you should take this holiday is not really based on any hard evidence, so you may get different suggestions. One suggestion is that you should stop every five years and then start again after one year if you are still at increased risk for fracture. Another way to decide is by getting tests called “bone markers.” These are tests measured from blood and urine specimens, which show how fast you are making new bone and how fast you are removing old bone. Some specialists feel that stopping the drug should be recommended when the markers get too low, meaning that bone activity has slowed down too much. This approach is also based on opinion, not hard evidence, which right now is lacking. Sometimes, stopping the drug may be risky (for example, multiple prior spine fractures while taking steroids), so good advice from an endocrinologist [en-doh-cri-NA-lo-jist] is important.

If you are going to have major dental work, you should stop the bisphosphonate some months before the procedure, and then start it again some months after all work is complete. Check with your dentist and endocrinologist.

Remember that these drugs do not replace the benefits of daily exercise, proper diet, and the correct amount of calcium and vitamin D. Opinions differ on how much and what type of calcium and vitamin D you should take. Check with your family doctor, gynecologist, and/or endocrinologist for professional recommendations.

Putting It All Together

All drugs have risks and benefits. The bisphosphonates can be life-saving when used properly (knowing when to start, when to stop, and when to start again, if necessary) and when taken along with a proper exercise regimen, healthy diet, and adequate intake of calcium and vitamin D.

Dr. Donald Bergman is in private practice in New York City and is board certified in internal medicine and endocrinology and metabolism. He has been Clinical Professor of Medicine at Mount Sinai School of Medicine in New York City. Dr. Bergman is past president of AACE and ACE. In 2003, during his AACE presidency, Dr. Bergman founded EmPower, previously known as “Power of Prevention”, a program that encourages people to partner with their physicians in establishing healthy lifestyles and demonstrating the importance of primary and secondary prevention. He serves as Executive Editor of EmPower Magazine.