According to the University of Michigan’s 2010 National Monitoring the Future study, prescription and over-the-counter medications rank second on the list of drugs abused by 12th-graders. (Marijuana was at the top of the list.) In 2009, there were nearly 4.6 million drug-related emergency-room visits nationwide. Almost 50 percent of them were attributed to adverse reactions to pharmaceuticals taken as prescribed, and 45 percent involved drug abuse. The Drug Abuse Warning Network estimates that of the 2.1 million drug abuse visits, 27.1 percent involved nonmedical use of pharmaceuticals such as prescription or OTC medications and dietary supplements.