June 2022

Hope on the Horizon: Trials target pharmacotherapy for methamphetamine use

A pharmacotherapy option for problematic methamphetamine use is being assessed in two trials conducted by Australia’s Orygen Institute.

“The best practice to treat substance use disorders is to combine both pharmaco- and psychosocial therapies,” says Orygen’s Dr Alexandre Guérin.

“Unfortunately, there’s no efficacious medication for methamphetamine use disorder, and medications are needed to bolster the effects of the psychosocial treatments that are already available.”

Ketamine as a cure?

Alex says there’s “very strong evidence” for ketamine in treating problematic cocaine use but no corresponding research for methamphetamine use.

Through its Methamphetamine Use in Young People Sub-anaesthetic Ketamine Open-label Trial (MASKOT), Orygen aims to address this shortfall.

The aim is “to test the safety and tolerability of two ketamine doses administered subcutaneously seven days apart” in participants with moderate to severe methamphetamine use disorder.

The potential for participants to seek ketamine outside the trial is front-of-mind for researchers.

While the therapeutic dosage is comparable to a low recreational dose of illicit ketamine, the controlled setting and drug purity make this a very different experience.

Alex says the first participant was “amazed at how different the effects of the ketamine were in the hospital to what they’d had recreationally.”

The best practice to treat substance use disorders is to combine both pharmaco- and psychosocial therapies

Dr Alexandre Guérin

What gives ketamine its pharmacotherapy potential?

“There’s been a lot of work done in depression where [ketamine] produces a very-rapid-onset anti-depressive effect that lasts for around about seven to 10 days,” says Associate Professor Gillinder Bedi.

This may be caused by “alteration to the neurobiology” which lasts beyond the acute drug effects.

While MASKOT lacks the funding for concurrent psychosocial treatment, Gill says that if “we can establish both the feasibility and the safety of ketamine in these early studies, we will then launch into a bigger study that will use that combination method.”

A cannabis-based approach

The second study is known as Cannabidiol – A Normal Pharmacotherapy for Lowering Methamphetamine Use, or CALM. Alex says the two studies’ aims and methodologies “are fairly similar”.

“However, what’s different here is that the CBD will be taken every day – daily capsules – and participants will be taking it for eight weeks.”

Progress to date

Twice delayed by COVID, the MASKOT study has just completed trialling its first participant.

“Realistically we’re at the end of the MASKOT funding,” says Associate Professor Gillinder Bedi, “But we have a little bit of wriggle-room. I think we can probably go on for another year.”

CALM will run for at least a year and is due to start in the next three months.

Who’s eligible?

Participant criteria:

—aged 15–25
—currently using methamphetamine
—have light to severe methamphetamine use
—used within previous two weeks
—want to reduce use.

“They don’t have to be actively taking steps to reduce, but they have to tell us that, yes, they are seeking to reduce their methamphetamine use,” Dr Alexandre Guérin says.

They can fill out an expression of interest form on our website, www.orygen.org.au