(CNN) Missouri Senator Claire McCaskill has launched an investigation into some of the country's leading prescription drug manufacturers, demanding documents and records dating back the past five years which indicate just what the companies knew of the drugs' risk for abuse as well as documents detailing marketing practices and sales presentations. Her office has sent letters to the heads of Purdue, Janssen/Johnson & Johnson, Insys, Mylan, and Depomed.
The companies were targeted based on their role in manufacturing some of the opioid painkillers with the highest sales in 2015.
The United States is in the midst of an opioid epidemic. According to the United Stated Centers for Disease Control and Prevention, since 1999, the number of drug overdose deaths involving prescription drugs has quadrupled. During the same time period, the sales of prescription drugs have also increased four-fold. In 2014, nearly 2 million Americans abused or depended on prescription drugs.
McCaskill is the senior Democrat on the Senate Homeland Security and Governmental Affairs Committee. This is not her first effort in attempting to uncover what has contributed to this epidemic. Earlier this year, she requested the Department of Justice Office of the Inspector General open an investigation into the role of drug distributors in the opioid epidemic. In addition, she's also been involved in investigating Medicare Part D's role in preventing abuse of prescription narcotics.
"I hear it everywhere I go: 'Drug overdose deaths, the vast majority of them related to prescription opioids or heroin, are single-handedly destroying families and communities across Missouri and the country,' and I refuse to just stand by and watch, we have an obligation to everyone devastated by this epidemic to find answers," McCaskill said in a statement.
This is not the first time the Senate has investigated the relationship of drug manufacturers in the opioid epidemic. In 2012 the Senate Finance Committee began looking into the relationship between drug manufacturers and pain organizations that advocated for their use. The findings have yet to be released.
In addition, counties and cities across the country have begun filing lawsuits against manufacturers for their roles in the drug epidemic. In Cabell County, West Virginia a complaint was filed (PDF) earlier this month alleging that between 2007 and 2012, drug companies and distributors, including pharmacies such as Walgreen's and Rite Aid, sold nearly 40 million doses of prescription opiates such as hydrocodone and oxycodone to county pharmacies. The county population during those years grew from just over 94,000 to just over 96,000 people. Similarly, nearby Kanawha County, West Virginia, filed a lawsuit (PDF) at the same time alleging the drug companies sold 66 million doses of these medications during the same time period when the county population ranged from about 191,000 to 192,000 residents.
The cities of Everett, Washington and Chicago, Illinois (PDF) have also filed similar complaints, alleging aggressive marketing and deceptive messaging about the risks of opioid painkillers.
"All of this didn't happen overnight. It happened one prescription and marketing program at a time. The vast majority of the employees, executives, sales representatives, scientists, and doctors involved with this industry are good people and responsible actors, but some are not. This investigation is about finding out whether the same practices that led to this epidemic still continue today, and if decisions are being made that harm the public health," said McCaskill.
In response to the investigation, Purdue Pharma issued the following comment: "The opioid crisis is among our nation's top health challenges, which is why our company has dedicated itself for years to being part of the solution. OxyContin accounts for only 2% of the opioid analgesic prescriptions nationally, but we are an industry leader in the development of abuse-deterrent technology and advocating for the use of prescription drug monitoring programs. We are reviewing Senator McCaskill's letter and will respond accordingly."