A new pill that slowly releases ketamine could treat those with severe depression without the narcotic side effects of the often-abused drug, researchers say.
Ketamine was first developed in the 1960s as an anesthetic, and its hallucinogenic effects led to it becoming a recreational drug used to get high.
However, growing research has shown that ketamine is effective for the quarter of people with depression who see little benefit from common antidepressant medications.
In many countries, ketamine has been prescribed to treat depression for years, but it causes side effects in patients such as high blood pressure and increased heart rate. There are also concerns that medical use of the drug could lead to addiction and dissociation (emotional detachment).
The new pill, described in the journal Nature Medicine, takes more than 10 hours to break down in the liver, Paul Glow, lead author of the study, told AFP.
"The really interesting feedback from patients is that there are no side effects: no euphoria, no dissociation," explained the researcher at the University of Otago in New Zealand. "I don't think these pills will attract people who abuse ketamine."
The phase II trial included more than 270 people with depression who had previously tried an average of four different antidepressant medications.
The study said that more than half of those who took ketamine pills entered the recovery phase from depression, while 70% of the placebo group relapsed after 13 weeks.
Julianne Allan, a mental health and addiction expert at Australia's Charles Sturt University who was not involved in the study, praised the experiment while stressing the need for more research.
She told AFP that ketamine is not suitable for everyone, and "the positive effects may fade over time."
There is “real enthusiasm” in the medical community for the potential of ketamine in treating depression, said Michel Hoffmann, a psychiatrist at Geneva University Hospitals. “For patients who do not respond to conventional medications, ketamine offers a way to avoid electroconvulsive therapy,” he explained.
This last-resort treatment, which involves sending electrical currents through the brain, has been shown to be effective.
Fears of an “opioid crisis”
Some psychiatrists are still reluctant to prescribe ketamine to treat depression, fearing that their patients will end up abusing the drug.
One potential benefit of fast-acting ketamine seen in previous research is that it could help patients who are considering suicide.
“There is concern that widespread use of ketamine could lead to a new opioid-style crisis,” said Riccardo De Giorgi, a researcher at the University of Oxford, in a 2022 BMJ editorial.
By eliminating ketamine's side effects, slow-release pills could alleviate some of these concerns.
There are still some side effects from the pill, the most common of which are headache, dizziness and anxiety.
More research, including Phase 3 trials, is needed before national medical agencies can review the drug, meaning it will be at least two or three years before patients can access the pill, Glo said.
That's a relief!
ReplyDelete