In the face of mounting evidence that GlaxoSmithKline withheld important safety data on their controversial drug Avandia, some doctors are abandoning use of this diabetes treatment.
Documents released Tuesday morning by the Senate Finance Committee suggested that for more than a decade, the drugmaker deliberately hid study results showing that Avandia could worsen certain risk factors for heart disease and was no better than its market competitor Actos.
The documents include several internal emails that record GlaxoSmithKline officials suggesting that certain unfavorable studies concerning the drug "never see the light of day to anyone outside of GSK."
"It's just not morally or ethically acceptable for companies to withhold data," says Dr. Steve Nissen, chair of Cardiovascular Medicine at the Cleveland Clinic and author of the original RECORD study, which raised public concern over Avandia's safety.
GlaxoSmithKline responded in an official statement that the studies were withheld because they failed to add new scientific information, but the growing evidence against the drug and the possibility of a cover-up is enough to deter some doctors from using the drug.
Release of these documents comes at the start of two days of advisory panel hearings to investigate Avandia's safety. The panel's recommendations could include keeping the drug on the market, calling for further restrictions or pulling the drug from the market altogether.
Avandia's safety was first publically called into question in 2007 when an analysis by Nissen found that those on the drug had a 43 percent higher risk of heart attacks and a 64 percent higher risk of dying from heart disease.
More recently, Food and Drug Administration associate director of drug safety Dr. David Graham called for Avandia to be removed from the market in a February report. He said the drug could be linked to about 500 more heart attacks and 300 more cases of heart failure each month than would occur if its competitor, Actos, were used exclusively.
Though the FDA's verdict is still out on Avandia's safety, the controversy raging over the drug has already had an impact on the doctors and patients who use the drug, physicians say.
"For my patients on Avandia, many of them have already asked to be switched to Actos," said Dr. Andrew Carroll, a family physican based in Chandler, Ariz.
"Based on prior studies I had read, I stopped prescribing Avandia about two years ago, and have been sticking with Actos," he added, saying that until the FDA makes a recommendation or further studies prove the drug is safe, he will be steering clear of Avandia.
Dr. John Sutherland, program director emeritus at Northeast Iowa Medical Education Foundation, said he has been slowly shifting his at-risk patients off Avandia, but said he has a few remaining patients on the drug.
Given the recent evidence that further risks were withheld by GlaxoSmithKline, he said that "we have made a decision to have all of [the few remaining patients on Avandia] switched to another therapy at this time."
Dr. Eric Larson, executive director of Group Health Research Institute, said he does not prescribe Avandia and even cancelled a research study on the drug after earlier reports of the drug's toxicity.