Patients with type 2 diabetes taking a widely prescribed drug are suffering more heart attacks, strokes and deaths than those taking another common treatment, according to a startling new study that raises the question whether the drug is dangerous. Diabetics taking a class of drugs called sulfonylureas, among the most commonly prescribed drugs for controlling blood sugar levels for over forty years, actually fared worse than the comparison drug, metformin, according to the study published in Annals of Internal Medicine.
Dr. Christianne Roumie, an internist with Vanderbilt University Medical Center in Nashville, Tenn., and colleagues examined data from more than 250,000 veterans who sought treatment for type 2 diabetes from 2001 through 2008, comparing those who took only sulfonylureas with those who took only metformin. Those who took sulfonylureas had a 21 percent increased chance of suffering adverse outcomes such as heart attack, stroke or death.
As this is an observational study, it s not clear whether sulfonylureas were hazardous on their own or whether metformin acts as a preventive. Roumie advocates a randomized controlled study be undertaken, as does an editorial accompanying the study.
ACSH s Dr. Gilbert Ross agrees, and calls the editorial mind-blowing. In it, Dr. Steven Nissen of the Cleveland Clinic describes how drug companies simply stopped underwriting randomized controlled trials of the effectiveness of diabetes treatments, following a study in 1970, which found that an older sulfonylurea drug did in fact increase diabetics chances of dying from heart attacks, following which the drug fell out of favor.
How did they get away with that? asks ACSH s Dr. Elizabeth Whelan. It s just incredible.
Dr. Ross agrees, and says that as a result there s a lot we don t know about the clinical effectiveness of diabetes treatments aside from their ability to keep blood sugar down. Drugs are often judged by how well they reduce surrogate markers such as blood-sugar levels, but evaluating diabetes treatments is tricky for some reason improving those surrogate markers in type 2 diabetics doesn t seem to translate into improved outcomes in terms of vascular disease, as well as visual, kidney and nerve complications.
This would be one area where I would be in favor of the government funding a study on long-term diabetes treatments and outcomes because the pharmaceutical industry isn t going to do it, Dr. Ross says.