Marijuana as a cure for opioid use? Nation's top drug scientist says she's skeptical

The head of the National Institute on Drug Abuse said there’s no evidence that marijuana weans people from opioid addiction – and promoting such treatment might deny people a chance at recovery.

The nation's research agency on drug use wants to assess cannabis ingredients as possible treatments for more than 2 million Americans with opioid-use disorder, NIDA Director Nora Volkow said this week. But there's not any evidence that marijuana works for opioid addiction, she said.

New York, New Jersey, Pennsylvania and Illinois allow marijuana as a treatment for addiction to opioids such as heroin, fentanyl and OxyContin. The Maryland General Assembly is considering a bill that would add opioid-use disorder to the state's list of qualifying medical conditions for marijuana.

Volkow said she worries people who substitute marijuana for the Food and Drug Administration-approved medications buprenorphine, methadone and naltrexone might be more likely to relapse.

"If you don’t treat it properly, your risk of dying is quite high," Volkow told the USA TODAY Editorial Board in a wide-ranging interview. "My main concern is by basically misinforming potential patients about the supposedly beneficial effects of cannabis, they may forgo a treatment that is lifesaving."

NIDA has two or three studies planned or underway to evaluate cannabis ingredients for opioid addiction. Still, Volkow said, scientific evidence does not support claims that marijuana helps people kick opioids. 

"I’m not saying it’s not possible," Volkow said. "Like anything else, we do science in order to determine and provide the evidence of whether it’s effective or not."

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"We're losing the battle" on opioids, said Maryland Delegate Cheryl Glenn, who sponsored a bill that would allow patients to take marijuana for opioid-use disorder.

Glenn's bill passed Maryland's Senate. A Maryland House hearing to amend the bill is scheduled for March 27. The legislation would require patients to first try other opioid treatments before using marijuana, a change Glenn opposes.

"My mother died from kidney cancer, and no one told the doctor he had to try this medication first, second or third," Glenn said. "I think the same respect ought to be given when you look at opioid disorders."

About 47,000 Americans died in 2017 from overdoses of heroin, fentanyl and other opioids – a "public health crisis of almost unprecedented scale," said Alan Leshner, chair of a study issued Wednesday on medication to treat opioid addiction.

The lengthy report from the National Academies of Science, Engineering and Medicine concludes that many Americans that could benefit are not getting buprenorphine, methadone and extended-release naltrexone. 

The report cites treatment barriers such as misunderstanding and stigma toward addiction, lack of education, a fragmented system of care, regulatory limits and patients' lack of money. Adolescents and young adults, rural residents and racial and ethnic minorities don't have equal access to treatment, according to the report, sponsored by NIDA and the Substance Abuse and Mental Health Services Administration.

Regulatory barriers prevent people from getting access to treatment, the report says. Methadone can be administered only at opioid treatment program clinics that are accredited and certified by SAMHSA, but the report says evidence shows delivering methadone through a medical practice is effective.

Few people who need medicine in prison, jail or under the supervision of drug court get the treatment they need. But the treatment can be effective, the report says, citing a 50 percent reduction in deaths among people on methadone or buprenorphine.