Ketamine Infusions Cut Migraine Pain in Half in New Study

Migraines are hell and researchers are looking into a new solution: Ketamine, the hallucinogen-turned-club-drug-turned antidepressant, may also help alleviate the crippling headaches for people who otherwise don't respond to treatment.

That's according to new research presented this weekend at the annual meeting of the American Society of Anesthesiologists in Boston. The study, conducted at Thomas Jefferson University Hospital, involved 61 participants with migraines, the recurrent throbbing or pulsing headaches that cause moderate to severe pain, and often include sensitivity to light and sound. Attacks can be debilitating, causing nausea and vomiting for some people.

About 12 percent of Americans get migraines—they're three times more common in women than men. The study consisted of people whose migraines hadn't responded to other treatments; that's known as having "intractable" migraines. People were referred by headache physicians, or neurologists who specialize in treating headaches, between January 2014 and December 2016, says study co-author Eric Schwenk. "Occasionally some patients with migraines have heard about ketamine therapy, and request to be given the treatment after talking to their headache physicians," says Schwenk, who's also director of orthopedic anesthesia at Thomas Jefferson University Hospital.

If you're only familiar with ketamine's reputation as a potent recreational hallucinogen—"Special K"—you might be surprised to hear migraine patients clamoring for it. But like a handful of other previously demonized "club drugs," ketamine has been earning researchers' respect. It's a well-known, safe pain reliever at low doses and an anesthetic at higher doses. Meanwhile, evidence continues to grow about its value as a fast-acting antidepressant, offering benefits in minutes that other drugs require weeks to provide. There's a reason emergency room doctor and Tonic contributor Darragh O'Carroll called it "my favorite medicine of all time."

Because of ketamine's potential as a migraine treatment, at least one sufferer flies to Los Angeles several times a year simply for some pain relief. At Jefferson, patients receive an intravenous infusion of ketamine continuously for three to seven days, under close supervision. Those who've never had the drug before may undergo some other tests to establish a baseline, Schwenk says.

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Among the 61 patients included in the study (17 men and 44 women), almost 75 percent saw an improvement in their migraine intensity. At admission, the average migraine headache pain rating was a self-reported 7.5 on a scale of 0 to 10. On leaving the hospital, the average pain rating was 3.4; less than half of the initial amount. Patients stayed just over 5 days, on average, and they experienced generally mild side effects including blurry vision and nausea and vomiting.

"Our study focused only on short-term relief, but it is encouraging that this treatment might have the potential to help patients long-term," Schwenk said in a statement. "Our work provides the basis for future, prospective studies that involve larger numbers of patients." The current study is retrospective, collecting results from a number of previous individual cases rather than a prospective study, which would enroll subjects at the same time under controlled conditions.

Richard Lipton, director of the Montefiore Headache Center at Albert Einstein College Of Medicine, echoed that sentiment. He did not participate in the study, but told Tonic he's encouraged by the results. "As ketamine is an approved drug, in expert hands, this treatment is an option for intractable patients," he says. "Future studies should more rigorously assess the short and long-term benefits of ketamine using blinding and a placebo control groups." As in, there should be a group of patients who get an infusion of a placebo, and the researchers shouldn't know which group is which.

One question future research might address why some patients respond to ketamine, while others don't—about a quarter in this study didn't respond. There's a clear division between the two, but, Schwenk says, "We have not been able to identify any factors that predict response yet."

The hospital plans to open an infusion center which can treat more patients and further the research. Schwenk believes ketamine may help with other painful chronic conditions, such as fibromyalgia and complex regional pain syndrome. Schwenk and his colleagues are betting they've just begun to unlock the potential of "Special K."

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