ADHD drug shows promise for treating meth addiction

A prescription medication used to treat attention deficit hyperactivity disorder (ADHD) could be repurposed as the first pharmacotherapy for people with methamphetamine dependence, according to a new study published in the journal Addiction.

As noted by addiction medicine specialist Professor Nadine Ezard, who is Director of the National Centre for Clinical Research on Emerging Drugs (NCCRED), there is currently no pharmacotherapy approved for treating methamphetamine dependence. But results from the landmark LiMA trial show that the psychostimulant known as lisdexamfetamine can drastically reduce the need to use methamphetamine among those who are dependent on the illicit drug.

As part of the trial, Ezard’s team at NCCRED — which is based at the National Drug and Alcohol Research Centre (NDARC), UNSW Sydney — recruited 164 adults who were dependent on methamphetamine and who had reported using the drug on at least 14 of the previous 28 days. Participants were randomly assigned to a 15-week regimen with lisdexamfetamine (one-week induction, 12-week maintenance on 250 mg/day and two-week reduction) or placebo, and tracked for four weeks after treatment.

Overall, those who received lisdexamfetamine had 8.8 fewer days of methamphetamine use on average during the 12-week maintenance phase than those in the placebo group. Those given the ADHD medication also had higher self-reported rates of treatment effectiveness (2.9 times higher) and treatment satisfaction (3.8 times higher) compared to participants given placebo. The effects were seen most strongly in the early weeks of the trial.

“While the beneficial effect waned towards the end of the treatment period, exploring the characteristics of ‘early responders’ in our study will be useful to understand who may benefit most from agonist therapies,” said Ezard, who was lead author on the study. She added that there were no unexpected safety concerns with high-dose lisdexamfetamine, with most adverse events deemed mild or moderate in severity.

An important limitation of the study was the high attrition rate of 39%; while this was consistent with other outpatient studies for methamphetamine use disorder, it impacted the statistical strength of the findings. Nevertheless, Ezard said the results were promising.

“While further research is needed, experienced clinicians could consider off-label prescription of lisdexamfetamine, with close monitoring of risks and benefits in line with current guidelines for psychostimulants, for people with methamphetamine use disorder,” she said.

People can access free and confidential advice about alcohol and other drugs by calling the National Alcohol and Other Drug Hotline on 1800 250 015.

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