WASHINGTON — New treatments for addiction to heroin or narcotic painkillers promise longer-lasting relief that may remove some day-to-day uncertainty of care: A once-a-month shot is now approved and a six-month implant is in the final testing phase.
The main treatment options have long been once-a-day medications – controversial methadone or a tablet named buprenorphine – that act as substitutes for the original drug, to suppress withdrawal and craving without the high.
Skipping a dose risks a relapse, but summoning the daily willpower to stick with treatment is “a formidable task,” says National Institute on Drug Abuse director Dr. Nora Volkow.
Last week, the U.S. Food and Drug Administration approved the monthly shot Vivitrol for long-term treatment of opioid addiction – to heroin or such painkillers as morphine, Oxycontin and Vicodin.
Vivitrol works differently than methadone or buprenorphine: It blocks the high if a recovering addict slips up, and it's not addictive.
Scientists had tried a daily version of Vivitrol's ingredient, naltrextone, years ago, but too many patients skipped pills. So Alkermes Inc. created the longer-lasting version first for alcoholism in 2006, and now opioid addiction. In a study of 250 opioid addicts in Russia, more than half of Vivitrol recipients stuck with therapy for the six-month trial. Better, 36 percent stayed completely drug-free, compared with 23 percent who received dummy shots.
Next in the pipeline: A matchstick-size implant that for six months at a time slowly oozes a low dose of buprenorphine into the bloodstream, to keep cravings tamped down. A large study published last week deemed the implant, called Probuphine, promising – just over a third of those patients, too, tested drug-free. Ongoing research partly funded by the government should show next spring if it's ready for FDA evaluation.
Which approach will work best for which patient? Scientists do not know yet; there are pros and cons to daily and long-lasting versions. Early next year, NIDA will directly compare once-a-month Vivitrol to once-a-day buprenorphine and behavioral therapy alone to help tell.
But longer-lasting options promise to help keep patients on track longer.
“Opioid addicts are notoriously bad at complying with their medication. They like to take drug holidays. They like to party on the weekend,” says Dr. Katherine Beebe of Titan Pharmaceuticals, which is developing the Probuphine implant.
And long-acting options also may help make substance abuse treatment more a part of mainstream medicine.
“To have these medications work effectively, you need to stay on them for long periods of time,” says Dr. Patrick O'Connor of Yale University School of Medicine. “We are really struggling to get the public and physicians to think of this more like a standard chronic disease – like diabetes, like cancer, like chronic lung disease – and not apply a special stigma to it.”
About 800,000 people in the U.S. are addicted to heroin and another 1.8 million either abuse or are dependent on opioid painkillers, Volkow says.
After initial detox, how to choose among long-term treatments?
Methadone is the cheapest but requires daily visits to a public clinic, many of which have waiting lists. Still, methadone may be the most potent choice for people who have abused heroin for many years, the hardest-to-treat patients, Volkow says.
Daily buprenorphine has increased access to care in recent years, because certain specially certified physicians can prescribe a month's supply of the pills at a time, for several hundred dollars.
Both methadone and buprenorphine require monitoring because they, too, can be abused, and some treatment programs will not use them because “their perception is you're changing one drug for another,” says Volkow.
Only about 45,000 people have used Vivitrol since its approval for alcoholism in 2006; the new approval paves the way for insurance coverage of the $1,100 shot for opioid addiction, too. It occasionally causes serious side effects such as liver damage or injection-site reactions. Also, Volkow says it won't work for people who need addiction care and pain relief at the same time – they'll still need buprenorphine.
But Volkow expects Vivitrol will attract painkiller addicts who would never consider other options, plus people struggling with daily therapy.