CVS has sent letters to some physicians in Florida informing them the pharmacy chain will not fill prescriptions they write for oxycodone and other Schedule II narcotic drugs, Reuters reports.

The letter, obtained by Health News Florida, said, “CVS Pharmacy, Inc. has become increasingly concerned with escalating reports of prescription drug abuse in Florida, especially oxycodone abuse.” The company says it sent letters to a small number of Florida physicians.

In October, U.S. Attorney General Eric Holder said that between 2005 and 2010, the number of oxycodone-related deaths in Florida increased by 345 percent. Last year, of the estimated 53 million oxycodone doses sold to medical practitioners in the United States, more than 85 percent were bought in Florida.