Irving Wainer, Ph.D., senior investigator with the Intramural Research Program at the National Institute on Aging, Baltimore said that the clinical use of ketamine therapy for depression is limited because the drug is administered intravenously and may produce adverse effects such as hallucinations and sedation to the point of anesthesia.
They have found that the HNK compound significantly contributes to the anti-depressive effects of ketamine in animals, without producing the sedation or anesthesia, which makes it an attractive alternative as an antidepressant in humans.
In the study where researchers used a rat model, rats were given intravenous doses of ketamine, HNK and another compound produced by ketamine metabolism known as norketamine. The effect each had on stimulating certain cellular pathways of the rats' brains was examined after 20, 30 and 60 minutes. Brain tissue from drug-free rats was used as a control.
It was found that HNK, like ketamine, not only produced potent and rapid antidepressant effects, but also stimulated neuro-regenerative pathways and initiated the re-growth of neurons in rats' brains. HNK also appears to have several advantages over ketamine in that it is 1,000 times more potent, does not act as an anesthetic agent, and can be taken by mouth, the authors report.
Interestingly, use of HNK may also serve as a future therapeutic approach for treating neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, the authors note.
The study is published in Anesthesiology, the official medical journal of the American Society of Anesthesiologists