The U.S. Justice Department sued Walmart Inc on Tuesday, accusing the retailer of fueling the opioid crisis in the United States and ignoring warning signs from its pharmacists, according to a court filing.
The retailer's shares fell about 2% following the news.
The lawsuit, filed in U.S. District Court in Delaware, accused Walmart of failing to take its gatekeeping duties as a pharmacy seriously.
Walmart, the world's biggest retailer, created a system that turned its 5,000 in-store pharmacies into a supplier of highly addictive painkillers, dating as early as June 2013, the lawsuit said.