WEDNESDAY, Sept. 9, 2003 (HealthDayNews) -- Diabetics who have mild heart disease or any problems with their kidneys could be at a greater risk of developing congestive heart failure if they take certain diabetes medications, according to a new study.
The study, published in the Sept. 9 issue of the Mayo Clinic Proceedings, reported on six cases of congestive heart failure in people taking pioglitazone (Actos) or rosiglitazone (Avandia) to help control their diabetes.
"We could not identify any other reason for the deterioration of their status," says the study's lead author, Dr. Abhimanyu Garg, a professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas. "These medications are known to cause fluid accumulation, so we gave the patients diuretic therapy and also withdrew the [pioglitazone or rosiglitazone] and they responded."
Dr. Luis Ospina, director of endocrinology and metabolism at William Beaumont Hospital in Royal Oak, Mich., doesn't think this study should alarm people who are taking these medications.
"These are excellent medications that we will be using more and more because they lower blood sugar and preserve endothelial function," he says, adding that that could in future studies prove to reduce heart attack and stroke risk.
The current study, he says, confirms what is already known about these medications. "The drug companies have warned that you have to be careful with the use of these medications in people with renal failure or a history of heart disease," says Ospina.
The researchers studied the records of six men, between the ages of 66 and 78 years, with type 2 diabetes who had gone to the emergency room at Dallas Veterans Affairs Medical Center emergency room. All six complained of shortness of breath, swelling of their feet, and weight gain, which are symptoms of congestive heart failure and pulmonary edema (fluid buildup in the lungs).
Congestive heart failure occurs when the heart can no longer pump enough blood to maintain adequate circulation. Because the heart doesn't pump properly, fluid often builds up in the lungs. Pioglitazone and rosiglitazone are already contraindicated for people with more advanced heart disease -- the type that causes physical limitations.
Four of the six people in this study had chronic renal insufficiency, which means that their kidneys weren't functioning normally. Only two had any previous signs of heart disease. Four of the six had high blood pressure.
They had been on the diabetes medications for between one month and 16 months. Three people developed symptoms within one to three months after the dose of their diabetes drug had been increased.
Doctors discontinued the diabetes medications and gave the six people diuretics, which are medications that help flush excess fluid from the body. All responded to this treatment.
The authors conclude that anyone with a history of congestive heart failure or chronic renal insufficiency should avoid taking these medications, and they suggest that further study be done on them.
"If somebody is taking these drugs and they develop severe swelling or severe weight gain, they are not tolerating the medication," says Garg, who recommends seeing a doctor immediately if you have these symptoms.
Garg says there are other options for controlling diabetes. First, he says, the "cornerstone of diabetes management" is diet and exercise. And, there are other medications, including insulin, that can help control blood sugar.
Avandia and Actos are members of a newer class of diabetes drugs called thiazolidinediones or glitazones, which increase the body's sensitivity to insulin. The first approved drug in that class, Rezulin, was taken off the market in 2000 after it was linked to dozens of cases of fatal liver disease.
At the time, the Food and Drug Administration said Actos and Avandia were "safer alternatives in this important class of diabetes drug." Watchdog groups like Public Citizen criticized the agency for not acting faster in withdrawing Rezulin and warned that the other drugs could cause problems, too.
More information
The National Institute of Diabetes and Digestive and Kidney Diseases offers information on diabetes medications and offers these suggestions for controlling your diabetes.
