Newer Monthly Injection Works Just As Well, But Requires Patients To Jump 'Detox Hurdle'

Nov 15, 2017

A much-anticipated new study found two popular opioid addiction medications are equally effective after treatment begins.

However, the newer of the two drugs, extended-release naltrexone, requires patients to detox before starting treatment, and many dropped out before starting the medication.

A relative newcomer to the opioid addiction treatment field, extended-release naltrexone (marketed as Vivitrol) has gained a foothold among treatment providers, especially those working with the criminal justice system, but until recently no major study had compared it to the more widely-used treatment, buprenorphine.

Now, researchers have found the two medications to be equally effective at preventing relapse once patients start treatment, according to a study published Tuesday in The Lancet.

The research also highlights a limitation for patients starting on extended-release naltrexone: it requires patients to detox before receiving their first treatment with the drug, creating a significant barrier to beginning treatment, according to Dr. Joshua Lee, associate professor at the NYU School of Medicine and lead author of the report.

“It’s going to take a few days or a week or more to get them on naltrexone in the first place,” he says. ”And that detox hurdle does not exist for buprenorphine.”

Still, the research indicates that it would be advisable for treatment providers to offer both medications, he said.

Relapse rates are extremely high if you don’t get onto and continue a medication,” said Lee.

The two medications work in very different ways. Buprenorphine (like another addiction medication, methadone) is a long-acting opioid that’s taken daily. There are decades of research showing that it helps reduce cravings and prevent withdrawal symptoms.

Naltrexone is an antagonist — it blocks receptors in the brain and prevents opioids from having any effect. Vivitrol, which is delivered as a monthly injection, was approved to treat opioid use disorder in 2010 and until recently, no studies comparing buprenorphine and Vivitrol had been published.

“We’ve had trials of each one, but not together,” said Lee. The new study followed 570 patients from inpatient detoxification centers. They were randomly assigned one of the two drugs for six months.

“Once people were on either one, they did reasonably well over time,” said Lee.

But because extended-release naltrexone can throw people into withdrawal if used too soon after opioid use, patients must first go through detox — abstaining from drug use — which often causes debilitating flu-like symptoms for several days. More than a quarter of patients assigned to naltrexone didn’t complete detox, and most of them relapsed.

Buprenorphine treatment doesn’t require patients to go through detox. “So up front there’s a clear clinical advantage,” said Lee. “Buprenorphine products are clearly easier to use.”

Some inpatient treatment centers may be ideologically opposed to starting someone on buprenorphine, particularly after detox, said Lee, but his study shows that it can be an effective option even starting in an inpatient setting. Relapse rates are higher among people who don’t use medications for their addiction.

“Detox episodes are brief,” he said. “They don’t generally last in terms of how you look a week later.”

He added that if patients enter treatment with hopes of getting on Vivitrol, but can’t make it through detox, they should be offered buprenorphine.The bottom line, he said, is that both medications should be widely available and offered to patients suffering from opioid addiction.

“We’re not doing a good enough job in this country of getting people into treatment and offering them these types of medications,” said Lee.“So were just going around undertreating the opiate epidemic.”

This story was produced by Side Effects Public Media, a news collaborative covering public health.