Study finds differences in black-box warnings

Black-box warnings (BBW) or safety labels on drugs differed widely across drugs and drug classes, according to a new study published in the Journal of Internal Medicine. 

Researchers at the University of Ioannina School of Medicine in Greece collected labeling information on the 20 top-selling classes of drugs in 2008 and found labeling differences in 9 of the 20 classes, representing 15 BBW labels.

Furthermore, the information for 10 of the 15 different BBWs was included in the labels of the same-class drugs as simple warnings or texts, while it was absent entirely in 5 BBWs. The median interval from the time the BBW had appeared in another drug of the same class was 66 months.

“Differences in BBW labeling in same-class drugs are common and shape impressions about the safety of similar drugs. BBW labeling needs to become more systematic,” the researchers wrote. Until large-scale, robust evidence on adverse events becomes routinely available, the current system of BBWs allows for flaws, the researchers added.