Science & Research

Drug may reduce marijuana dependency

Half of medicated participants drop out due to adverse side effects, experts doubtful of results

Senior Staff Writer
Wednesday, January 27, 2016

A University study released earlier this month suggests that an anti-epilepsy drug is effective in reducing the amount of marijuana smoked by young adults, but not necessarily the frequency of smoking.

Yet some scientists doubt the validity of the results, in part because half of the study’s medicated participants dropped out before the study concluded — some due to adverse side effects from the drug.

The study, published in the journal Addiction Biology, tested the effects of topiramate on heavy cannabis users ages 15 to 24. Topiramate was administered to 40 of the study participants, who also received three 50-minute sessions of motivational enhancement therapy, in which patients learn strategies to reduce their usage. The remaining 26 participants received only the therapy over the trial’s six weeks, in addition to a placebo pill.

The researchers used self-reports and urine toxicology to measure rates of marijuana use. Participants reported the amount of marijuana used on a particular day by weighing out oregano as an estimate, according to the study.

“In both conditions in the study, we saw significant reductions in how quickly people used,” said Robert Miranda, associate research professor of psychiatry and human behavior and lead author of the study. “But in the topiramate condition we also saw that when kids did smoke, they smoked less.”

Ryan Vandrey, associate professor of psychiatry and behavioral sciences at Johns Hopkins School of Medicine, disagreed with that conclusion. There was no quantitative change in the amount of marijuana use by each group on days when participants smoked, Vandrey said. “There is a difference between groups, but that difference existed at the beginning.”

Miranda found the results to be “promising in some ways,” he said. “The biggest drawback of the study was that a lot of people didn’t really tolerate the medication very well.”

Sixty-six individuals began the six-week trial, but only 39 finished it — 52.5 percent of the topiramate group participants and 23.1 percent of the placebo group participants dropped out of the study.

Of the 21 dropouts from the topiramate group, 67 percent cited side effects as their reason for withdrawing. A multitude of side effects were reported by participants, including neurocognitive and gastrointestinal distress.

“The results show that this medication has one serious drawback in that it is poorly tolerated, and that’s something that has often been reported for topiramate,” said Margaret Haney, professor of neurobiology and co-director of the Substance Use Research Center at Columbia University Medical Center. “It certainly showed some interesting findings with a decrease in marijuana use, so that was encouraging. But the dropout rate would seem to make it a non-starter.”

In future research, Miranda would like to investigate who tolerates topiramate best and possibly direct the treatment toward that group, he said. “I’m not sure what our next steps will be,” he added.

These findings illustrate that further research could examine how anti-epileptic drugs influence marijuana dependence, Haney said.  “Anti-epilepsy drugs have shown promise for a lot of drugs of abuse, so there’s no reason not to pursue it for marijuana.”

Miranda is currently investigating topiramate’s possible impact on alcohol abuse. The study is expected to conclude later this year.

In her lab, Haney has studied a few drugs that could have potential as treatment for marijuana dependence, such as tetrahydrocannabinol agonists. These medications behave somewhat like THC, so they can “reduce the withdrawal and decrease the desire to use marijuana” without the same risk of abuse.

Still, the Food and Drug Administration has yet to approve any medication for treating cannabis dependence, Miranda said.

In treatment for marijuana dependency, a psychosocial intervention, such as the motivational enhancement therapy involved in the study, is used more commonly. “Lots of good scientists have been trying lots of medications, and we haven’t found one that works really well yet,” Vandrey said. “Exactly what those medications are is kind of the golden goose right now.”


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  1. Vape Escape says:

    The second paragraph says it all.

    When you take away actual medicine and give people poison, bad things happen.

  2. Christopher Barker says:

    Exactly, and well put.
    We’re supposed to ingest a harmful man made chemical to help us stop ingesting something that is completely natural and has no level of toxicity?
    In what universe is this supposed to make sense? WTF…

  3. Christopher Barker says:

    There’s an even better way to stop using cannabis in case it’s been under reported, and it doesn’t enrich bigpharma,. It’s called “stop smoking pot if you want to stop smoking it”.

    If you are incapable of stopping, I put forth the theory that you are not at all addicted to marijuana, but are in fact addicted to being addicted, to anything.

  4. Immortal Illumined says:

    growing industry in America? Legal Marijuana, coming to your town very
    soon….#1 crop in California and LEGAL in ALL west coast states, #MarijuanaSavesLives

    the west coast thanks you a trillion (dollar$), filling any order anytime.

    27 states and the DOC allow marijuana but not 1 southern state, lol, nobody denies freedom like the south.

    Deaths by alcohol: Millions.
    Deaths by tobacco: Millions.
    Deaths by guns: Millions.
    Deaths by prescription drugs: Quadrupled in decade.
    Deaths by marijuana: 0, EVER……(Centers for Disease Control Statistics).

    new studies on animals by the FEDERAL GOVERNMENT claim marijuana kills some
    cancers and reduces the size of others…1000s of Cancer research
    centers sucking Billion$ and yet not 1 study with marijuana decades
    later, not 1…and you think they are trying to cure cancer? #AmericanIdiots

  5. Immortal Illumined says:

    i’ve worked with 10,000 plus marijuana patients……NEVER seen this needed…..anything to make a $ though eh?

    always trying to force man made PHARMA down our throats instead of a NATURAL PLANT

  6. Dingus Mcgee says:

    writing this article is an idiotic way of bringing ones own credibility into question. prior to its undertaking, the people behind this study had already concluded that “marijuana dependency” is a social problem which requires medical intervention. their professional credentials are moot at this point.

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