Methamphetamine, widely referred to as meth, crystal, or ice, is a potent and highly addictive stimulant.
Globally, around 7.4 million individuals are addicted to or dependent on this substance, facing numerous health dangers including paranoia, suicidal thoughts, cardiac issues, strokes, accident-related injuries, and an increased likelihood of premature death.
Currently, no approved medications exist worldwide to treat methamphetamine dependence.
However, there is hope in a cost-effective, safe, and readily accessible drug traditionally used to treat depression. A recent trial of mirtazapine, published in JAMA Psychiatry, demonstrates that individuals who use it reduce their meth intake.
Limited Treatment Options
Australia has one of the highest per capita rates of methamphetamine dependence in the world.
With no approved medications for meth addiction globally, treatment options are scarce.
Available treatments include counseling, detoxification or withdrawal programs, and long-term residential rehabilitation. Unfortunately, accessibility is challenging, and there are high dropout rates. The majority of rehab participants relapse.
Community-based, more advanced treatments like contingency management, which sets goals and incentives, are more successful but not widely available.
Despite the absence of approved treatments for meth use, some doctors prescribe medications that have shown potential in clinical trials.
Off-label medications include prescription stimulants like methylphenidate, lisdexamfetamine, modafinil; the anti-smoking aid bupropion; the opioid antagonist naltrexone (sometimes combined with bupropion), and antidepressants.
However, these drugs may not be effective and could pose unnecessary side effects or safety hazards.
Mirtazapine’s Potential
Recent studies suggest that the antidepressant mirtazapine could offer some promise.
Two trials conducted in the United States at an outpatient research clinic in San Francisco, California, found that mirtazapine reduced methamphetamine use.
These initial trials involved a small group of patients (60 and 120 respectively) who were closely monitored. The patients were at risk of HIV, specifically men and transgender women who had sex with men. Women and individuals with depression were not included.
Thus, an Australian team sought to determine if mirtazapine could yield similar benefits when used by doctors in community clinics for a broader and more diverse patient group.
Research Findings
The Tina Trial involved 339 meth-dependent participants from six outpatient clinics in Australia, representing a larger and more varied sample.
At the trial’s outset, participants had used meth on average 22 out of the previous 28 days.
Participants were randomly divided to either receive mirtazapine (a 30-milligram tablet daily) or a placebo for 12 weeks. Researchers monitored meth use over this period.
Those on mirtazapine reduced their meth use more significantly than those on the placebo (an average reduction of seven out of 28 days compared to 4.8 days).
Mirtazapine’s advantage was modest: a reduction of 2.2 days in usage out of 28 days.
This benefit was consistent regardless of the presence of depression at the start of the trial.
Although the reduction in meth use is minor, it marks a significant advancement in the absence of alternative medication options.
Researchers believe mirtazapine directly impacts methamphetamine dependence, separate from its depression-reducing effects.
This suggests that mirtazapine may act directly on brain systems tied to drug reward and potentially restore functions disrupted by long-term meth use.
The study reported no unexpected safety concerns using mirtazapine for meth dependence, with drowsiness and weight gain being the most common side effects.
Not a Complete Solution
Mirtazapine does not offer an immediate “cure” for meth dependence. However, in the absence of any globally approved medications for meth use, it represents a crucial step in mitigating methamphetamine-related harms.
Mirtazapine is inexpensive, safe, and widely available, with many physicians already familiar with its use for treating depression.
Related: Common Antidepressants May Have Another Surprising Effect on Your Brain
As a take-home medication, it allows users to avoid daily clinic visits or intensive medical supervision.
Being “off patent,” generic versions are affordably priced.
For mirtazapine to be routinely prescribed for meth dependence outside of clinical trials, regulatory approval is necessary, requiring research evidence like that from the Tina Trial.
Meanwhile, doctors can prescribe mirtazapine off-label, following guidelines provided by the Royal Australian New Zealand College of Psychiatrists on off-label prescribing.
Further information on the Tina Trial can be found here.
If you have concerns about your own or someone else’s drug or alcohol use, contact the National Alcohol and Other Drug Hotline at 1800 250 015 for free and confidential support, available 24/7.
[Editor’s note: For readers in the US looking for information on drug and substance abuse support, click here.]
Rebecca McKetin, Associate Professor, National Drug & Alcohol Research Centre, UNSW Sydney and Shalini Arunogiri, Addiction Psychiatrist, Associate Professor, Monash University
This article is republished from The Conversation under a Creative Commons license. Read the original article.
