A new drug that could dramatically improve outcomes for people who are addicted to opioids or alcohol is being tested in Vancouver.

St. Paul’s Hospital is the only Canadian site that’s involved in a pilot study headed by the U.S. National Institute on Drug Abuse’s clinical trial network of the effects of Vivitrol, or naltrexone, on people with HIV who also have opioid or alcohol addiction. Approved for use in the U.S., it blocks the brain’s ability to experience the effects of alcohol and drugs such as heroin.

What makes the injectable medication unique is that its effects last up to 30 days, explains Keith Ahamad, a family doctor certified in addiction medicine who is on a local research team affiliated with the B.C. Centre for Excellence in HIV/AIDS. The drug’s duration is significant because it makes compliance far more feasible for people hooked on substances like heroin who otherwise have few options aside from methadone, which requires daily trips to a pharmacy for treatment.

“People often don’t take their medication [methadone] when they’re totally entrenched in the chaos of their addiction,” Ahamad says in a phone interview. “If they don’t, their viral loads go up,” which typically leads to more rapid disease progression, “and that’s when they come down with opportunistic infections. You need to be on medication, and if you can’t take them every day, you also run the risk of quickly getting drug resistance.

“The beauty of this medication…is that it is an opiate blocker, and what that means is it sticks onto the receptors that drugs like morphine attach to and blocks their effects completely,” he adds. “For opiate-addicted patients, it essentially gives them a sheet of armour. If they were to use heroin—which, interestingly, gets turned into morphine in the body; that’s the active component—it’s rendered completely inert.”

Several other factors appear to make Vivitrol effective, says Ahamad, who sees patients at St. Paul’s and also works at Vancouver Detox and the Vancouver Jail.

“Because it’s a once-a-month injection, people are not physically dependent on the medication, so there’s no withdrawal and no euphoria, no reinforcing, no abuse potential. And there are very, very few side effects and very, very few drug-drug interactions.

“There’s no risk of overdose and no risk of sedation or all these cognitive side effects that people don’t talk about with other medications for opioids addiction,” he adds.

Ahamad is quick to emphasize that methadone has its place; for many people, it’s life-saving. However, it doesn’t work for everyone.

“This medication offers another tool in our toolbox,” he says. “For diseases like depression or hypertension or diabetes or asthma, there are many different medications to treat those, and if people fail treatment for whatever reason, they try another medication.…Often with addiction, we don’t see that. With opiate addiction, we don’t have that many tools to treat it and we need more.

“We need studies like this to get Health Canada to make these medications available for untreated addiction. Aside from human suffering—and that goes well beyond the patient to the whole family; there’s intergenerational trauma—the cost to society is astronomical, with incarcerations and hospital admission. We estimate for every dollar we put into addiction treatment, we save between $4 and $7.”

Another reason the drug holds so much promise, Ahamad says, is that it may be equally effective in treating alcohol addiction (with or without simultaneous opioid addiction). In some people, drinking alcohol causes the release of excessive amounts of endorphins, which can create the pleasurable feelings associated with drinking. By attaching to certain receptors in the brain, Vivitrol appears to reduce alcohol’s rewarding effects.

“When I say ‘drugs’, I include alcohol,” he says. “I think we minimize the harm associated with alcohol. Alcohol addiction is so hugely undertreated.…By blocking that pathway, we can get rid of the euphoria that’s associated for some people and there’s no withdrawal. It’s not shown to increase abstinence but it does seem to decrease heavy drinking, and heavy drinking is what leads to consequences.”

He says he’s already seen patients who were accustomed to drinking 40 standard drinks a day—whether that was beer, hard liquor, wine, or other substances—become able to stop after one or two drinks.

“Their disease is so bad they’re drinking Listerine and hand sanitizers, and all that goes away. They’re drinking some days but not all, and on the days they do drink they have one or two,” Ahamad says. “Their life is altered. It’s literally like a switch has gone off.”

In the first large randomized trial, which was published in the Journal of the American Medical Association in 2005, Vivitrol reduced heavy drinking in alcoholics by 25 percent. A subsequent study, published in the Lancet, found that 90 percent of heroin addicts who were prescribed Vivitrol became abstinent compared to 35 percent of patients given a placebo.

Twenty-five HIV-positive patients are being recruited in Vancouver for the study, which is also in progress in Chicago with the same number of participants. The Vancouver portion of the project is being led by Dr. Evan Wood, codirector of the Urban Health Research Initiative at the B.C. Centre for Excellence in HIV/AIDS and medical director of addiction services at Vancouver Coastal Health and Providence Health Care. Once this pilot study is complete, the institute’s goal is to conduct a much larger one on an international scale.