Academics from the National Drug Research Institute (NDRI) are collaborating with institutions from across Australia to investigate the efficacy of a promising medication to treat dependence on crystalline methamphetamine, also known as crystal meth or ice.
The research team, led by Associate Professor Rebecca McKetin, has been awarded a $1.55 million National Health and Medical Research Council grant to conduct a world first out-patient trial of the medication N-acetyl-cysteine (NAC) for ice dependence. NAC is an inexpensive generic medication, currently approved for various health issues including chronic obstructive pulmonary disorder and paracetamol overdose.
Collaborators at Deakin University have been trialling NAC for various neuropsychiatric disorders and, under this trial, they will team with McKetin and researchers at Monash University, the Burnet Institute, the University of Wollongong and the University of Newcastle to trial NAC for methamphetamine dependence.
What is crystal meth?
Crystal meth is highly addictive stimulant. It rapidly boosts the amount of the natural chemical dopamine in reward areas of the brain, providing the user with a rush of euphoria, confidence and energy. Side effects can include reduced appetite, insomnia, rapid heart rate and breathing, a rise in blood pressure, irregular heartbeat, aggression, anxiety and mental confusion.
Long term use can cause changes to the neurochemistry of the brain, leading to concentration problems, changes in mood, psychiatric symptoms, disrupted sleep patterns and physical health complaints. These neurochemical changes also cause tolerance and craving, leading people to become dependent on the drug and making it hard for them to control their use.
How does crystal meth impact individuals and society?
Dependence on crystal meth is a significant global public health issue, and Australia has one of the highest levels of use and dependence in the world. Since 2010, the number of dependent users in Australia has increased from approximately 72,000 to 160,000, which has resulted in additional demands on overwhelmed drug treatment services, particularly in rural and remote areas.
There are currently no approved medications to treat withdrawal from, or dependence on, crystal meth, which is a significant impediment in providing treatment for people who use the drug. Historically, medication options have focused on agonist therapies, which substitute another drug, such as off-label dexamphetamine for methamphetamine, to normalise brain function and reduce cravings (similar to the way methadone is used for opioid dependency).
How does NAC work?
NAC is a new approach, which targets the changes that occur in the brain with drug dependence. It restores homeostasis to those brain systems, making it easier for the person to control their drug use. NAC has shown signs of efficacy for several drugs, including cocaine, cannabis and tobacco.
It has particular potential for methamphetamine dependence because of its multiple actions, which aid in the management of comorbid psychiatric symptoms and protect against methamphetamine neurotoxicity.
Also appealing is NAC’s relatively low cost, and it’s suitability to be delivered as a prescribed over-the-counter medication, thereby reducing the demand on overloaded drug treatment services.
“If found to be effective, this medication has the potential to be a cost-effective treatment option for ice dependence.”
“A recent Phase I trial of NAC use in humans found a large reduction in methamphetamine craving, signalling the need for a Phase II trial to confirm this benefit and examine NAC’s effects on other clinically relevant endpoints. We will conduct a world-first Phase IIb double-blind randomised placebo-controlled trial to assess the safety and efficacy of NAC as a medication for methamphetamine dependence,” said Associate Professor McKetin.
“This 12 week trial will be powered to detect a reduction in methamphetamine use and changes in a range of related clinical outcomes. If found to be effective, this medication has the potential to be a cost-effective treatment option for ice dependence.”
The multi-site N-ICE trial will be conducted in collaboration with Deakin University, Monash University, the University of Wollongong, the University of Newcastle, La Trobe University, the Burnet Institute and Turning Point.
The trial is expected to commence in late 2017 and run until 2019.