Clinical trial reveals promising two-drug combo to reduce methamphetamine use

A recent clinical trial has shown promise in reducing methamphetamine usage through a two-drug therapy, according to research led by UCLA. The trial, known as ADAPT-2, tested the efficacy of combining injectable naltrexone with extended-release oral bupropion (NTX+BUPN) and found it significantly reduced methamphetamine use for up to 12 weeks after treatment began.

Participants who received the NTX+BUPN combination experienced a 27% increase in methamphetamine-negative urine tests, indicating a reduction in drug use. In comparison, participants in the placebo group exhibited only an 11% increase in methamphetamine-negative tests. This difference highlights the potential effectiveness of the NTX+BUPN therapy in combating methamphetamine addiction, for which there are currently no FDA-approved medications.

The study, which will be published in the journal Addiction, was spearheaded by Dr. Michael Li, an assistant professor of family medicine at UCLA's David Geffen School of Medicine. Dr. Li emphasized that the lack of FDA-approved treatments for methamphetamine use disorder, coupled with the rising number of methamphetamine-related overdoses over the past decade, underscores the importance of these findings.

Methamphetamine use has been on the rise globally, with the number of users increasing from 33 million in 2010 to 34 million in 2020. The United States has seen a fivefold increase in methamphetamine overdose deaths from 2012 to 2018. Similar trends are observed in Canada and Australia.

In response to this ongoing crisis, the National Institute on Drug Abuse (NIDA) Clinical Trials Network has supported various clinical trials, including ADAPT-2, to explore different pharmacological treatments for methamphetamine use disorder. The ADAPT-2 trial was conducted between May 23, 2017, and July 25, 2019, across eight sites, including UCLA. It involved 403 participants, with 109 assigned to the NTX+BUPN group and the remainder to the placebo group during the first stage.

The latest findings represent the second stage of this multi-site trial. While the first stage had demonstrated that the two-drug combination was effective at six weeks, it remained unclear whether this efficacy would persist over a longer period. During the second stage, researchers conducted urine tests on participants at weeks seven and 12, and again post-treatment at weeks 13 and 16, to compare the NTX+BUPN group with the placebo group.

The researchers noted that further studies are needed to determine whether the treatment effect lasts beyond 12 weeks and continues to reduce methamphetamine use. They acknowledged that changes in stimulant use are often gradual and that sustained abstinence might not be achieved within a typical 12-week trial. Therefore, future clinical trials should aim to quantify changes in methamphetamine use beyond 12 weeks and identify the optimal duration for treatment with this medication.

The study's co-authors include Brendon Chau, Thomas Belin, Steven Shoptaw of UCLA, and Thomas Carmody, Manish Jha, Elise Marino, and Dr. Madhukar Trivedi of the University of Texas. The research was funded by the National Institute on Drug Abuse, the U.S. Department of Health and Human Services, the U.S. National Institute of Mental Health, and the O'Donnell Clinical Neuroscience Scholar Award from the University of Texas Southwestern Medical Center.

This breakthrough offers hope for those battling methamphetamine addiction and paves the way for future research to better understand and optimize treatment strategies.