KETAMINE can be considered a novel therapy for treatment-resistant depression, according to the Royal Australian and New Zealand College of Psychiatrists, although some experts say the recommendation is premature.
Last month, the college published a clinical memorandum on its website regarding ketamine for depression, saying despite its short-term efficacy, there was “limited evidence” to recommend ketamine as a viable treatment for treatment-resistant depression. It advised the therapy be used under research trial conditions. (1)
The college has acknowledged that some patients wanted access to the therapy outside of trials and that some psychiatrists were keen to provide it off-label. In these cases, the college recommended the treating psychiatrist “consider such treatment as novel or innovative treatment” and clearly explain this to the patient, providing detailed information on the risks.
The clinical memorandum said prescribing psychiatrists should discuss its use with peers, “preferably including a second opinion”, and recommended they seek institutional review and ethics committee consideration.
Dr Stephen Hyde, a Tasmanian psychiatrist and author of the book Ketamine for depression published earlier this year, welcomed the college’s new position. (2)
“I believe this is a considered and humane response to the suffering our patients endure”, he told MJA InSight.
Dr Hyde said while he supported research into the field, many patients could not wait several years for trials to be completed. “In the meantime, people are suffering and dying prematurely from treatment-resistant depression.”
He said he had been treating 18 patients with treatment-resistant depression for the past year with low-dose sublingual ketamine, saying 70% had responded and 35% remitted with no problems with dependence or addiction.
However, not all psychiatrists have welcomed the college’s new stance.
Professor Philip Mitchell, of the school of psychiatry at the University of NSW, who is involved in ketamine research, said the college’s statement was “too liberal” and gave a licence for ketamine’s inappropriate use.
“There is insufficient evidence to support ketamine going into the clinical armamentarium yet, although it’s potentially a very exciting treatment”, he told MJA InSight.
“We have seen very dramatic results reported in various studies, but the results wear off very quickly, and we don’t yet have evidence for the safety and efficacy of giving repeated administrations.”
Professor Mitchell said there had already been “excessive uptake and commercial exploitation” of ketamine for depression.
A chain of clinics known as the Aura Medical Corporation was reportedly charging more than $1000 for a course of eight ketamine injections for patients with depression. The company was forced to close in July this year amid negative publicity after it was linked to the controversial erectile dysfunction company Advanced Medical Institute. (3)
Associate Professor Graham Barrett, a GP and neurophysiologist at the University of Melbourne, was the medical director of Aura for one month before resigning in March. He told MJA InSight he was disillusioned that the company was “profit oriented and not giving enough time to follow up patients”.
Professor Barrett now has a voluntary agreement with the Australian Health Practitioner Regulation Agency not to prescribe ketamine. However, he told MJA InSight he still believed the drug should be legitimised for off-label use in the 40% of patients with depression who did not respond to existing antidepressants.
“There is now abundant evidence that ketamine will relieve depression in three-quarters of patients who don’t respond to existing antidepressants”, he said. “The alternative, favoured by many practitioners because it usually works, initially at least, is ECT [electroconvulsive therapy]. Unfortunately, it is now shown beyond doubt that ECT causes irreversible brain damage, amnesia and dementia.” (4)
Professor Colleen Loo, of the Black Dog Institute who is leading a major study into ketamine for treatment-resistant depression, said the clampdown by health authorities on clinical use of the drug was “not surprising”.
In an editorial in this week’s MJA, Professor Loo wrote that the risks of acute treatment with ketamine included induction of psychotomimetic effects and elevation of blood pressure, although these were typically transient. (5)
“If ketamine is prematurely applied clinically to treat depression, before research has determined how (and if) it can be effectively and safely used to achieve lasting remission of depression, the end result may be disillusionment and even abandonment of this otherwise promising therapy”, she wrote.
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