In February 2017, Klobuchar and thirty other senators signed a letter to Kaléo Pharmaceuticals in response to the opioid-overdose-reversing device Evzio rising in price from $690 in 2014 to $4,500 and requested the company answer what the detailed price structure for Evzio was, the number of devices Kaléo Pharmaceuticals set aside for donation, and the totality of federal reimbursements Evzio received in the previous year. In March 2017, Klobuchar was one of twenty-one senators to sign a letter led by Ed Markey to Senate Majority Leader Mitch McConnell which noted that 12 percent of adult Medicaid beneficiaries had some form or a substance abuse disorder in addition to one third of treatment administered for opioid and other substance use disorders in the United States being financed through Medicaid and opined that the American Health Care Act could "very literally translate into a death spiral for those with opioid use disorders" due to the insurance coverage lacking and not having the adequate funds to afford care oftentimes resulting in individuals abandoning substance use disorder treatment. In June 2018, Klobuchar co-sponsored the bipartisan STATES Act proposed in the 115th U.S. Congress by Massachusetts Senator Elizabeth Warren and Colorado Senator Cory Gardner that would exempt individuals or corporations in compliance with state cannabis laws from federal enforcement of the Controlled Substances Act. In February 2018, Klobuchar introduced the CARA 2.0, a follow-up bill to the Comprehensive Addiction and Recovery Act (CARA) that included imposing a three-day initial prescribing limit on opioids for acute pain along with increasing services to promote recovery and attempting to widen the availability of treatment. At a news conference, Klobuchar described CARA 2.0 as "a blueprint for the country in terms of training on naloxone and in terms of authorization for money." In December 2018, Klobuchar was one of 21 senators to sign a letter to Commissioner of Food and Drugs Scott Gottlieb stating their approval of the actions of the Food and Drugs Administration to hinder youth access to e-cigarettes and urging the FDA "to take additional, stronger steps to prevent and reduce e-cigarette use among youth." In January 2019, Catherine Cortez Masto announced that she and Klobuchar were sponsoring legislation authorizing "the largest purchaser of prescription medications, Medicare, to negotiate drug prices and to hold pharmaceutical companies accountable for the rising prices of prescription drugs." In June 2019, Klobuchar was one of fifteen senators to introduce the Affordable Medications Act, legislation intended to promote transparency through mandating pharmaceutical companies disclose the amount of money going toward research and development in addition to both marketing and executives' salaries.