New York Mayor Michael Bloomberg is launching a task force to fight the growing prescription drug abuse epidemic in the city, after officials identified 21 pharmacies that account for about one-fourth of the city’s oxycodone Medicaid reimbursements.

During the past 20 years, New York City has experienced a 10-fold jump in the use of prescription opioids, The Wall Street Journal reports. The number of opioid-related emergency rooms visits jumped 40 percent between 2004 and 2009. “These drugs are being used to do more than just kill pain,” Bloomberg said in a statement to the newspaper. “They are being misprescribed and misused, resulting in addiction and overdoses.”

The task force will include health and law-enforcement officials. The group’s first round of recommendations is expected in January.

The city’s Department of Health and Mental Hygiene will release guidelines for physicians on how to prescribe opioids safely, according to the article. The guidelines recommend that for most patients with acute pain, a three-day supply of opioids is enough, even though doctors regularly prescribe much more.