CHICAGO -- A significant number of patients with diabetes are inappropriately prescribed a common drug that potentially could kill them, a study suggests.
The study on metformin, also sold as Glucophage, is one of several on diabetes published in Wednesday's Journal of the American Medical Association. It's the first JAMA issue devoted entirely to research on diabetes, which has reached epidemic levels and afflicts about 17 million people nationwide.
Glucophage helps the body use insulin and is among the most common drugs for Type II diabetes, which is linked to obesity and is sometimes called adult-onset, although it has started showing up in children.
The drug package insert warns that Glucophage can cause a rare side effect called lactic acidosis, a buildup of lactic acid in the blood that is fatal in about half of all cases. The label says it should not be used by patients with kidney disease or those who are taking drugs for heart failure.
But nearly one-fourth of patients met at least one of those criteria in the study, which involved 100 Glucophage outpatient prescriptions from a University of North Carolina hospital pharmacy in Chapel Hill. Patient charts also were studied, and none had developed lactic acidosis, said lead researcher Cheryl Horlen, who now works at Campbell University in Buies Creek, N.C.
The study "may underestimate the frequency of contraindications and it is difficult to determine whether clinicians are aware they are prescribing metformin against a black-box warning," the researchers said, referring to highlighted cautionary information required by the government on labels of drugs that could have serious side effects.
University of Pittsburgh researchers and several recent European studies found similar rates of inappropriate use, and Horlen said the problem isn't unique to the University of North Carolina.
Bonnie Jacobs, a spokeswoman for Glucophage maker Bristol-Myers Squibb Co., said the warnings "are clearly outlined" on the label.
Diabetes impairs the body's ability to produce or make proper use of insulin, resulting in elevated blood sugar levels that can damage the kidneys, heart, eyes and other organs.
"I can't imagine anybody in the United States who doesn't have someone in their family or some close friend with diabetes. It's such a big problem right now," JAMA editor Dr. Catherine DeAngelis said.
Recent research from Harvard Medical School and Public Citizen Health Research Group suggested that doctors don't pay close enough attention to drug warning labels, a problem also raised by the Food and Drug Administration.
Dr. Malcolm Taylor, president of the Association of Black Cardiologists, said patients' lack of knowledge about diabetes drugs might be partly to blame, and he said many are unaware of diabetes' major complications.