A clinical trial on a two-drug therapy for methamphetamine use disorder successfully decreased the use of the highly addictive drug for up to 12 weeks after treatment initiation. Participants in the ADAPT-2 clinical trial who were given a combination of injectable naltrexone plus extended-release oral bupropion (NTX+BUPN) experienced a 27% increase in methamphetamine-negative urine tests, indicating reduced usage. In comparison, the placebo group only had an 11% increase in negative tests. It is important to note that there is currently no FDA-approved medication for methamphetamine use disorder.A UCLA-led research suggests that patients who have been treated with a combination of injectable naltrexone plus extended-release oral bupropion (NTX+BUPN) may continue to have reduced methamphetamine usage for up to 12 weeks after starting treatment. The study, called ADAPT-2 clinical trial, showed that participants who received NTX+BUPN had a 27% increase in methamphetamine-negative urine tests, while the placebo group had an 11% increase in negative tests. These findings will be published in the journal Addiction, and they are important for the treatment of methamphetamine use disorder. There is currently no FDA-approved medication for this disorder.Dr. Michael Li, the lead author of the study and assistant professor-in-residence of family medicine at the David Geffen School of Medicine at UCLA, pointed out that while there isn’t much attention on methamphetamine, overdoses involving the drug have significantly increased over the past ten years.
Worldwide, methamphetamine use has been on the rise, with the number of users increasing from 33 million in 2010 to 34 million in 2020. In the US, overdose deaths related to methamphetamine have increased fivefold from 2012 to 2018, and similar trends are observed in Canada and Australia.
To address this ongoing crisis, the National Institute on Drug Abuse (NIDA) Clinical Trials Network has provided support for various interventions.The ADAPT-2 trial and other similar trials have been conducted to study the effects of different pharmacological treatments for methamphetamine use disorder. ADAPT-2, which took place from May 23, 2017, to July 25, 2019 and involved eight trial sites including UCLA, had 403 participants. Of these, 109 were in the drug combo group and the rest were in the placebo group during the first stage of the trial.
The most recent findings are from the second stage of the multi-site trial. The initial stage had shown that the two-drug combination was effective at six weeks, but the question remained whether the intervention would continue to be effective over a longer period.
During the second phase, the researchers administered urine tests to the participants at weeks seven and 12. They also conducted additional tests at weeks 13 and 16 after the treatment, comparing the group receiving NTX+BUPN with the placebo group.
The researchers emphasize the need for more studies to determine if the effects of drug treatment last longer than 12 weeks and lead to further reductions in methamphetamine use.
According to the researchers, previous trials for stimulant use disorder treatment indicate that changes in use are gradual, similar to their findings. These changes are unlikely to result in sustained abstinence in a typical 12-week trial and are dependent on the duration of treatment.
The authors of the study concluded that there is a need for further clinical trials to assess the effects of MA use beyond 12 weeks and to determine the best duration of treatment with this medication. The study was conducted by researchers from UCLA and the University of Texas, and was funded by the National Institute on Drug Abuse and the U.S. Department of Health and Human Services.The Emmes Company’s Statistical Coordinating Center is funded by HHSN271201400028C, while the Data and Statistics Center is also supported by the same organization. Additionally, the U.S. National Institute of Mental Health provides funding through K23MH126202, and the University of Texas, Southwestern Medical Center supports the O’Donnell Clinical Neuroscience Scholar Award.
