Closing in on Ketamine Therapy

Major depression was successfully treated by ketamine in a recent clinical trial

(RxWiki News) Relief from symptoms of major depression can be hard to find. But doctors have been repurposing an anesthesia medication in experiments to find rapid relief for patients with major depression.

A recent clinical trial tested the use of the anesthesia medication ketamine to treat major depression.

The results of the trial showed that ketamine helped the majority of patients within 24 hours and lasted as long as seven days.

"Seek treatment for depression."

Dan Iosifescu, MD, associate professor of psychiatry, and James Murrough, MD, assistant professor of psychiatry, at the Icahn School of Medicine at Mount Sinai, led a clinical trial to investigate the use of ketamine in patients with major depressive disorder.

Ketamine is most often used for anesthesia in humans and animals. According to the authors, several small studies have tested the use of ketamine in patients with major depression.

Treating major depressive disorder can be difficult, as antidepressant medications can take several weeks to take effect. Also, antidepressant medications do not always work for people with major depressive disorder. 

Patients that don’t experience relief from at least two different types of antidepressants are referred to as “treatment resistant.”

For this clinical trial, the researchers recruited 72 patients with treatment-resistant major depression to be in one of two groups.

Patients in first group were given an intravenous (IV) infusion of ketamine for 40 minutes. Patients in the second group were given an IV with midazolam, another type of anesthesia that doesn’t have any known antidepressant qualities, for 40 minutes.

After 24 hours, the researchers evaluated the patients for symptoms of major depression with the Montgomery-Asberg Depression Rating Scale. The depression scale has a range from 0 to 54, with scores above a 20 labeled as moderate depression and scores above a 34 labeled as severe depression. 

The results of the study showed that 64 percent of the patients who had received ketamine experienced some symptom relief, compared to 28 percent of the midazolam group.

Patients in the ketamine group reported an average 16.5-point reduction on the depression rating scale compared to the average 8.8-point reduction experienced by patients in the midazolam group.

After seven days, the researchers evaluated the patients again and found that 46 percent of the ketamine group still had some symptom relief compared to only 18 percent of the midazolam group.

No serious side effects were found in any of the patients in either of the two groups.

So far, this trial has been the largest clinical trial to test the use of ketamine in patients with treatment resistant major depressive disorder.

The study authors concluded that the ketamine IV helped provide rapid relief and large antidepressant effects in patients with major depression within 24 hours and lasted for up to seven days.

While ketamine is already on the market for anesthesia purposes, it has not yet been approved to treat depression. Therefore, the cost of a ketamine IV for the treatment of depression would not be covered by insurance and could run as high as $3,000 or more.

Ketamine has been used as a drug of abuse, so patients should never use ketamine with the intention of self-treatment for depression.

“Ketamine’s history dates back to the 1960’s when it was synthesized from PCP (phencyclidine) by the pharmaceutical company Parke-Davis.  It received FDA approval in 1970 and was first used as an anesthetic for soldiers of the Vietnam War," Jason Poquette, BPharm, RPh, told dailyRx.  

"Aside from this indication as an anesthetic, and some off-label treatment of pain or neuralgia, ketamine has had a rather limited spectrum of medical uses in humans.  But this recent study has opened the door for perhaps a new field of opportunity in using ketamine for the rapid reversal of treatment-resistant depression." 

"The results of the study were impressive, with ketamine approximately doubling the likelihood of a positive response when compared to the “active” placebo used by the control group.  It was the addition of the active placebo (midazolam) which differentiated this study from those done earlier with inactive placebo controls."  

"Long-term improvement remains uncertain, and the necessity of administering ketamine by IV infusion is a challenge, but the results of this study help confirm that ketamine deserves significant attention and study for future application in patients with resistant depression," said Dr. Poquette, who was not involved with this study.

This study was presented on May 20 at the annual meeting of the American Psychiatric Association in San Francisco, CA. The research presented has not yet been published in a peer-reviewed journal. 

No trial funding information was made available to the public.

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Review Date: 
May 22, 2013