Avandia: Is it a safe option for diabetes treatment?

A Mayo Clinic diabetes specialist answers questions about Avandia and diabetes treatment.

Maria Collazo-Clavell, M.D.

The safety of the popular diabetes drug rosiglitazone (Avandia) remains a hotly debated topic. If you have type 2 diabetes and take Avandia as part of your diabetes treatment plan, you might be left wondering what to do. Here, Maria Collazo-Clavell, M.D., an endocrinologist specializing in diabetes at Mayo Clinic, Rochester, Minn., answers common questions about Avandia.

How does Avandia work?

Avandia is one of many oral medications designed to control blood sugar. Avandia lowers the amount of sugar in your blood by making your tissues more sensitive to insulin, a hormone that regulates the absorption of sugar into your cells. Avandia belongs to a class of drugs known as thiazolidinediones.

What's the concern about Avandia?

Avandia and other thiazolidinediones have potentially serious risks, including swelling and weight gain that leads to or worsens heart failure and rare, but potentially life-threatening, liver problems. A study first published online in the New England Journal of Medicine in May 2007 raises the possibility of an increased risk of heart attack and, possibly, an increased risk of death from cardiovascular causes — serious concerns given the fact that diabetes dramatically increases the risk of various cardiovascular problems, including heart attack, stroke and high blood pressure.

Some of these findings were supported in a separate study published in the Journal of the American Medical Association in September 2007. In this study, Avandia significantly increased the risk of heart failure and heart attack. However, researchers didn't note an increase in the risk of premature death.

The concern about heart risks has prompted Avandia's manufacturer to include a black box warning — the most serious safety warning — on Avandia labels. The black box warning cautions that the drug may cause or worsen heart failure and may potentially increase the risk of heart attack.

Is the link between Avandia and heart attacks well established?

Despite the black box warning about heart risks, the potential link between Avandia and heart attacks remains a hotly debated topic.

The study that spurred public debate about Avandia and the risk of heart attacks was an analysis of pooled data from available clinical trials of Avandia. A preliminary analysis of results from a continuing study of Avandia doesn't associate the drug with an increased risk of death. The September 2007 study found a significantly increased risk of heart failure and heart attack, but not premature death.

What are the statistics?

Among people who took Avandia, the May 2007 study estimated that one person experienced a heart attack for every 1,000 people at low risk of heart attack. Among people who take an alternative diabetes medication, the estimated risk is lower — one heart attack for every 1,300 people.

It's important to note that information for the May 2007 study was collected from trials of people who had prediabetes or newly diagnosed diabetes. It's possible that the increase in heart attack risk would be different for older adults who have a long history of diabetes and who have a higher risk of heart problems in general.

In the September 2007 study, Avandia approximately doubled the risk of heart failure and increased the risk of heart attack by more than 40 percent.

Is it safe to continue taking Avandia?

If Avandia is part of your diabetes treatment plan, continue taking the drug as prescribed until you have the opportunity to talk to your doctor. Although an increased risk of heart attack is nothing to take lightly, the risk isn't considered an emergency. It's much riskier to stop taking a diabetes medication on your own.

If Avandia is effectively lowering your blood sugar level and you're not at high risk of cardiovascular problems, you and your doctor may decide that it's best to continue taking the drug. If you're concerned about the potential risks of Avandia — especially if you're at high risk of heart attack or other cardiovascular problems — you and your doctor may opt to stop using Avandia.

Are there alternatives to Avandia?

Many alternatives to Avandia are available in various classes of drugs. In addition to insulin, other options may include metformin (Fortamet, Glucophage, others), glipizide (Glucotrol), exenatide (Byetta), sitagliptin phosphate (Januvia) and others.

Keep in mind that all medications have benefits and risks. For example, some diabetes medications may promote weight loss or weight gain. Others may cause nausea or low blood sugar. Sometimes liver problems are a concern.

What about other drugs in the same class as Avandia?

Actos includes a black box warning about an increased risk of heart failure. However, previous studies of Actos show possible cardiac benefits — such as lowering triglycerides. In fact, in a separate study also published in the Journal of the American Medical Association in September 2007, Actos actually lowered the risk of heart attack, stroke and death.

What's the bottom line?

Researchers will continue to study the safety and effectiveness of Avandia, as well as other diabetes medications. In the meantime, the decision about which diabetes medication is best for you depends on many factors — including your blood sugar level and the presence of any other health problems. Your doctor might even combine drugs from different classes to help you control your blood sugar in several different ways.

If you and your doctor decide that it's best to switch from Avandia to another diabetes medication, carefully follow your doctor's instructions. You may need to monitor your blood sugar level more frequently or take other precautions while you're adjusting to the new medication.