If you think typical side effects labels on prescription drugs have been expanding in size in recent years, you're right: the average label now lists 70 reactions per drug--a number that appears to be overwhelming physicians looking for appropriate treatments for their patients, according to researchers at the Indiana University School of Medicine and the Regenstrief Institute.
The researchers, who analyzed more than 5,600 drug labels with more than half a million labeled effects, found that more commonly prescribed drugs averaged nearly 100 side effects. In the upper range, some labels had as many as 525 reactions, researchers said in their study, which appears in the current issue of the Archives of Internal Medicine.
A high number of side effects found on a drug's label does not necessarily mean that the drug is unsafe, said lead author Jon Duke, MD, a Regenstrief Institute investigator and assistant professor of medicine at Indiana. "In fact, much of this labeling has less to do with true toxicity than with protecting manufacturers from potential lawsuits," he said in a statement.
However, the expanding labeled side effects can overwhelm physicians, he added. While the Food and Drug Administration has taken steps to dissuade these "overwarnings," the current "information overload is the rule rather than the exception," he said.
When the researchers looked at multiple classes of medications and their labeling, they found the greatest number of side effects to be in antidepressants, antiviral medications, and newer treatments for restless legs syndrome and Parkinson's disease. Overall, medications typically used by psychiatrists and neurologists had the more complex labels, while medications used by dermatologists and ophthalmologists had the least complex.