The national study involved 185 patients with advanced cancer, 93 of whom received the drug ketamine while the other 92 received a placebo.
The results, published last week in the prestigious international Journal of Clinical Oncology, not only showed identical benefit between the two groups but revealed significantly higher rates of toxicity and other side-effects for those receiving ketamine.
Chief Investigator and Professor of Palliative and Supportive Services, David Currow said the results of the study have highlighted the potential harm that can be caused by prescribing “off label” – that is, using drugs in ways other than originally intended – without adequate trials.
“The role of ketamine in routine clinical care for chronic, complex cancer pain is not in any way supported by this study. The result is resoundingly negative,” Professor Currow said.
“At sub-anaesthetic doses, ketamine has been shown to help in post-operative pain relief; so the trial of it in cancer-related pain, where the nerve itself is damaged, was a very logical step,” he said.
“The question is, can you take information from one patient population and just automatically apply it to another population? The short answer is you can’t.”
Professor Currow said that “robust data” were needed to inform the care of people with advanced life limiting illnesses.
“These people deserve exactly the same quality of care that anyone else gets in the health system. In fact, they’re more at risk than anyone else of adverse outcomes,” he said.
“They’re frail, they’re often on many medications but they’re not necessarily old – one in three is under the age of 65 in Australia.”
This study is the first to be published by PaCCSC, which is funded under the national Palliative Care Program and supported by the Australian Government Department of Health and Ageing to test the effectiveness of various medications in order to improve symptom management and quality of care in patients living with a terminal illness.
Other research currently underway includes the world’s largest study on the use of anti-psychotic medications to treat acute confusion, or delirium.
“It’s going to inform practice around the world, not just in palliative care but in the frail and elderly, people after operations or major trauma, people with acute infections: all are at very great risk of becoming acutely confused,” Professor Currow said.