Yet another study has found that Avandia and Actos, popular diabetes drugs, raise a patient’s risk for heart failure. These new findings are just the latest to cast doubts on the safety of these medications, which have been under scrutiny for some time.
Actos and Avandia are drugs known as thiazolidinediones, or TZDs and are used to lower blood sugar. These drugs have been under scrutiny since May when a study of 42 clinical trials conducted by the Cleveland Clinic showed that patients taking Avandia had a 43% higher risk of having a heart attack, and a 64% higher chance of sudden cardiac death. The Cleveland Clinic study also found that Avandia nearly doubled the risk for heart failure. That study caused the Food & Drug Administration (FDA) to convene a hearing of an advisory panel to discuss Avandia’s heart attack risks. While the panel agreed that patients using Avandia do face a greater risk of heart attack, and the diabetes drug should bear the strictest FDA warnings, it stopped short of recommending that Avandia be pulled from the market entirely. Both Actos and Avandia already carry warnings that they may cause or worsen congestive heart failure, a condition in which the heart does not pump blood efficiently.
Published in the Lancet, the latest study was conducted by researchers at the Lahey Medical Center in Massachusetts. Like most other research into these drugs, it was a meta-analysis, meaning that it pooled data from many different clinical trials. This particular study took data from seven trials where more than 20,000 patients with type 2 diabetes or pre diabetes were given Actos or Avandia. The overall risk of heart failure in all patients was around 72% percent higher than it is the general population. Patients with a history of heart disease and heart failure had he highest risk of developing heart failure when using Actos or Avandia. However the Lahey study did not find an increased risk of cardiac death in patients using these drugs, something that other research has pointed to.
The authors of the Lahey study claim that the data they examined was more robust than those the Cleveland Clinic analyzed. The researchers had a panel of experts determine if any heart attacks had occurred in the clinical trials they analyzed. Also, the seven clinical trials used in the Lahey study had all been previously published.
While the Lahey researchers found that Actos and Avandia both were effective in controlling blood sugar, an accompanying editorial in the Lancet criticized researchers for using reduced blood sugar levels as evidence of a drug’s success. Rather, it said they should focus more on patient outcomes such as quality of life and survival. The editorial recommends that drug companies conduct further clinical trials of their medications after they are on the market. “Regulatory agencies must hold manufacturers’ feet to the fire to ensure that these are performed,” it says. “Unless limitations on the understanding, analysis, and communication of drug safety issues are addressed, the TZDs will simply become the latest in a series of preventable drug disasters.
