The disks could only be used to treat addiction if they delivered a different drug than hydromorphone because that drug is not approved by the FDA for treating addiction, only for pain, he said. Only methadone and buprenorphine currently have that stamp from the FDA.
There is, however, a growing need for new treatments for addiction to prescription drugs such as oxycodone and morphine, said Dr. Michael Fingerhood, an associate professor of medicine at the Johns Hopkins University.
The number of admissions to Maryland Alcohol and Drug Abuse Administration-funded treatment programs for prescription drug addiction doubled to 7,000 between 2007 and 2010, according to the state Department of Health and Mental Hygiene.
Others, especially teens, find unused opioids in their parents' medicine cabinets. About 2,500 American teens use prescription drugs every day to get high for the first time, according to the Partnership for a Drug Free America.
Maryland joined dozens of other states this year in creating a database to track filled prescriptions so doctors know when someone may be shopping for extra drugs, but the system is not yet up and running.
The trend is likely to continue until doctors stop prescribing so many addictive drugs, said Fingerhood, who treats addicts.
He said addicts still often have pain, but the pain becomes difficult to treat because they can't be handed more pills. This is where Dr. Grossman's disk may come in.
Not for treating the addiction — there already is a similar rod implant developed by Titan Pharmaceuticals Inc. awaiting FDA approval that contains buprenorphine for that purpose. But to treat the pain, said Fingerhood, who also is the director of the division of chemical dependence at Hopkins Bayview Medical Center.
"It's a great option for pain," he said. "It's treated poorly now in this population because they can't take traditional pills. … And I think implants are going to be the wave of the future with other medications as well."