Skip to content
My WebMD Sign In, Sign Up

Diabetes Health Center

Font Size

New Diabetes Drugs Bad for Bones

Avandia -- and Probably Actos -- Speeds Up Bone Loss
WebMD Health News
Reviewed by Louise Chang, MD

Avandia Bad for Bones

Dec. 3, 2007 -- The diabetes drug Avandia promotes osteoporosis not only by slowing bone growth but also by speeding up bone loss. Actos, the only other drug in the same class, likely does this as well.

The finding, from mouse experiments by Salk Institute researcher Ronald M. Evans, PhD, and colleagues, helps explain why clinical studies show increased bone fracture risk in people taking Avandia.

Bones stay healthy through an ongoing process called remodeling. The body is constantly breaking down and rebuilding bone. This system of resorption and deposition is tightly controlled with many checks and balances.

"The drug shifts this balance on both sides," Evans tells WebMD. "People taking this drug have somewhat decreased bone deposition -- that is a known action of the drug, resulting in mild bone loss. But what we discovered is it increases bone resorption in a fairly robust way."

Avandia belongs to the glitazone class of drugs, which enhances a chemical signal called PPAR-gamma. One effect of the drug is to increase the body's sensitivity to insulin. But another effect, Evans and colleagues now show, is to activate the bone-eating cells called osteoclasts.

"I would expect to see the same thing with Actos, although we did not actually do that experiment," Evans says. "But it is almost certainly a drug-class effect because the mediator of this effect is the target of both drugs."

Bone Risk From Avandia, Actos

"This is not meant to scare people," Evans asserts. "Only Avandia and Actos act in this unique way, and these drugs are an overall benefit for the patients who take them."

But bone expert J. Edward Puzas, PhD, professor of orthopaedics at the University of Rochester, N.Y., says the new finding confirms something bone researchers have been worrying about.

"This is a nicely done study of how these drugs stimulate the cells that eat away at bone. This leads to lower bone mass and higher bone fragility," Puzas tells WebMD.

Puzas is worried because bone changes occur very slowly, so researchers may only be beginning to appreciate the scope of the problem.

Philip T. Rodgers, PharmD, clinical associate professor of pharmacy at the University of North Carolina, hopes the new findings will make doctors pay more attention to the bone risks posed by Avandia and Actos.

"There is an underappreciation of the risks of osteoporosis with these drugs," Puzas says. "I don't think doctors are paying enough attention to testing the bone-mineral density of people on these drugs."

Mary Anne Rhyne, a spokeswoman for Avandia maker GlaxoSmithKline, says the company is already aware of the drug's bone risks. She notes that the company recently updated the drug's label to reflect new data on fracture risk.

"We have a comprehensive, ongoing clinical program to better understand the mechanism of fractures," Rhyne tells WebMD.

While they worry about the bone risks from Avandia and Actos, both Puzas and Rodgers note that the drugs' benefits outweigh the risks for many patients.

Both suggest that doctors should screen patients for osteoporosis before starting them on Avandia or Actos therapy. And both suggest that patients taking the drugs should discuss bone-protection strategies with their doctors.

Meanwhile, Evans says the new findings should help researchers come up with new diabetes drugs that improve insulin sensitivity without stimulating bone loss.

Evans and colleagues report their findings in this week's advance online issue of Nature Medicine.

Is This Normal? Get the Facts Fast!

Check Your Blood Sugar Level Now
What type of diabetes do you have?
Your gender:

Get the latest Diabetes newsletter delivered to your inbox!


Your level is currently

If the level is below 70 and you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.

People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.

Congratulations on taking steps to manage your health.

However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.

Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.

Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.

One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.

Did You Know Your Lifestyle Choices
Affect Your Blood Sugar?

Use the Blood Glucose Tracker to monitor
how well you manage your blood sugar over time.

Get Started

This tool is not intended for women who are pregnant.

Start Over

Step:  of 

Today on WebMD

Woman holding cake
man organizing pills
Close up of eye

Woman serving fast food from window
Can Vinegar Treat Diabetes
Middle aged person
are battery operated toothbrushes really better

Prediabetes How to Prevent Type 2 Diabetes
type 2 diabetes
food fitness planner
Are You at Risk for Dupuytrens Contracture

WebMD Special Sections