A new University of the Sunshine Coast study has found small amounts of liquid ketamine administered in a clinical setting can significantly reduce symptoms of post-traumatic stress disorder, with fewer side effects.

Published today, the study by researchers from the new National PTSD Research Centre at the University of the Sunshine Coast, is the first open-label clinical trial to explore the feasibility, safety and tolerability of low-dose oral ketamine for PTSD treatment.

Ketamine - a short-acting anaesthetic medication – is being tested as a fast-acting treatment for PTSD and depression. However, this off-label use is usually delivered through injections or infusions which need to be administered in a hospital.

In the UniSC study, 73 percent of participants reported that their PTSD symptoms had reduced by more than half, one week after finishing the oral ketamine treatment, which involved one ketamine drink each week for six weeks. One month after receiving their last dose, 59 percent of participants, many with PTSD their entire adult lives, said their symptoms remained less than half what they were when they started the trial.

Senior investigator Professor Dan Hermens said the finding suggested oral ketamine was potentially a more accessible, affordable option for PTSD patients, with a lower chance of adverse reactions than intravenous (IV) ketamine.

“Despite extensive studies on IV ketamine infusions, there are gaps in understanding the most effective dosage levels and the best way to administer the drug as a treatment,” Professor Hermens said.

“Our study found oral ketamine – administered in small amounts to study participants once a week as a drink in a clinical setting – is a safe, well-tolerated form of therapy that could be integrated into ongoing treatment programs of PTSD patients,” he said.

In addition, the oral ketamine PTSD study group reported feeling significantly less depressed, less stressed and less suicidal after the treatment. They said they had better sleep, a better quality of life, improved social and occupational functioning and overall wellbeing.

“That oral ketamine can improve a spectrum of mental health symptoms in a short period of time is significant, as over 90 percent of people diagnosed with PTSD also experience a psychiatric disorder such as suicidal ideation, anxiety, alcohol use disorders and depression,” Professor Hermens said.

“Importantly, all participants reported that side effects from oral ketamine had resolved before their discharge from the study,” Dr Quigley said.

“Overall, oral ketamine is also cheaper than IV or intranasal ketamine, potentially making to available to more people.”

The researchers said that amount of oral ketamine administrated over the treatment period was gradually increased as a deliberate aspect of the trial protocol.

“Adopting an initial lower dose was designed  to assess each patient's tolerance to oral ketamine before gradually increasing it, striking a balance between minimising side effects and maximising the achievable benefits,” Dr Quigley said.