Medicine for Your Bones

As stated in my first post on bones, the cornerstone of bone health is to make sure that there is enough material (calcium) delivered to the building site in conjunction with a regular stimulus to rebuild (weight bearing exercise).  For some, this is all that will be needed but if medications are needed, they will be much more effective in the setting of a proper calcium supply and regular exercise.  The medications used to treat weak bones fall in three main categories.  Each category has its advantages and each has downsides as well.  They can be separated broadly as 1) hormonally acting medications 2) bisphosphonates and 3) stimulators of bone growth.

It has long been recognized that the female hormone estrogen protects against bone loss.  It is after menopause that bones start to rapidly become more brittle.  For years, women were treated with estrogen after menopause.  It was felt that this kept their bones strong, reduced hot flashes and had beneficial effects on heart disease.  With time and further studies it has been shown that these hormones may actually promote heart disease and they certainly have an adverse effect on increasing one's risk for breast cancer.  The use of these medications has appropriately dropped off.  There are a group of medications that are similar to estrogen that are in use, the most common being Evista.  It is similar to estrogen in improving bones.  It likely is protective in breast cancer.  It is not certain what the effects are on the heart but it may make hot flashes worse.  Like estrogen, it may increase the risk of blood clots in the legs.  Though Evista is not typically used first line it is a reasonable choice in the right patient.

Bisphosphonates are the mainstay of treatment for osteoporosis.  This includes Fosamax (alendronate), Actonel (residronate) and Boniva (ibandronate).  These medications work by decreasing the activity of osteoclasts (the bone eaters).  By so doing, the osteoblasts have a chance to catch up and bone growth occurs.  Without question, they have shown to decrease the rate of fractures of the hip and spine.  However, there are some important points to understand in regards to the safety and long term use of these medications.  First, they are not easily absorbed and must be taken on an empty stomach.  They can be quite irritating to the esophagus and can cause an ulcer.  It is, therefore, important to take the medicine sitting upright and to stay upright for at least 30 minutes afterwards. There have been reports of a condition called osteonecrosis of the jaw with the use of these medications.  This is bone degeneration under the teeth.  It is mostly seen in patients who have been given these drugs for cancer and in very large doses through an IV.  It is exceedingly uncommon as part of a treatment plan for osteoporosis.  Lastly there have been news reports stating that there may be an increased risk of femur (leg) fracture if the medicines are used for a long period of time (more than ten years).  It turns out that these reports have been over blown but an important consideration remains.  Remembering that the medicine works by blocking absorption, if there is no action by the osteoclasts (bone eaters), eventually new bone will be put down on top of old bone.  Depending on one's level of bone loss when therapy was started, I recommend a "holiday" off of the medicine after 5 or ten years to make sure that bone turnover is occurring.

For patients who have severe osteoporosis with fractures that has not been adequately treated with the above medications or who cannot tolerate those medications, a relatively new therapy called Forteo can be given.  This works through parathyroid hormone actions and stimulates new bone growth.  It works quite well but should not be given for more than two years.  It is a daily injection that has to be given by the patient  and is quite expensive, thus limiting its use.  Another new medication is available called Prolia which I would only recommend be given by physicians well versed in osteoporosis.  If you have any questions, please let me know.