US Pharm. 2009;34(11):24. 

The FDA launched a Web page for consumers with information on how to dispose of certain drugs, including high-potency opioids and other potentially harmful controlled substances. The FDA recommends that these medicines be disposed of by flushing them down the sink or toilet to keep them away from children and others. Medicines not listed should be thrown away in the household trash after mixing them with some unpalatable substance, such as coffee grounds, and sealing them in a bag or other container. Another option is to dispose of them through drug take-back programs, federal and state law permitting.