If you've ever had kidney stones, erupted wisdom teeth or disjointed joints, you've probably received take-home bottles of prescription opioids such as oxycodone to manage the pain.

A few leftover pills might even be in your medicine cabinet right now — even if they were prescribed months earlier.

And that's become a big problem for the state of Minnesota because, as Dr. Charles Reznikoff put it, "Now I have a bottle full of addictive drugs in my medicine cabinet."

The rising number of addictions has drawn attention to the overprescribing of opioid painkillers, and to the excess supply that ends up getting stolen by experimenting teens or by hooked adults. One study found that 67 percent of surgery patients ended up with surplus narcotics at home, and that 90 percent didn't know what to do with them, said Reznikoff, an addiction specialist with Hennepin County Medical Center.

Flushing them isn't environmentally friendly; studies have found traces of medicines in drinking water supplies.

And yet the U.S. Food and Drug Administration allows exactly that — deeming the danger of keeping unused narcotics around to be worse.

Environmental advocates would prefer that people take these medications to hazardous waste dumps, or at least dispose of them in household trash by mixing them with unpalatable substances such as kitty litter and sealing them in plastic.

The Minnesota Board of Pharmacy is pursuing another option: legislation that permits pharmacies to collect customers' old drugs for disposal.

Right now, state law requires that county disposal and law enforcement agencies receive controlled substances. A bill to add pharmacists as legal collectors stalled last year, but will be considered this session.

Many pharmacists are eager to provide this service for confused customers, even if they bear some expense and their receptacles must meet federal standards, said Cody Wiberg of the pharmacy board.

"They have to be set up like old-fashioned mailboxes," he said. "You put something in, you can't get it back out."