'Impressive' Results for Intranasal Ketamine in Chronic, Refractory Migraine

Eve Bender

June 14, 2023

Intranasal (IN) ketamine may be a feasible treatment alternative for people with chronic, refractory migraine who don't respond to other medications, new research shows.

Half of the study participants who used IN ketamine for chronic, treatment- refractory migraine in a new retrospective cohort study reported it as "very effective" and over one third said it boosted their quality of life.

Dr Hsiangkuo Yuan

"In our study, we showed that with even a few uses per day, intranasal ketamine can still improve patients' quality of life," lead investigator Hsiangkuo Yuan, MD, PhD, told Medscape Medical News. Yuan is associate professor of neurology at Thomas Jefferson University in Philadelphia and director of clinical research at the Jefferson Headache Center.

He added that "multiple medications failed these patients, and the majority of patients were having daily headaches. So, if anything works, even partially and shortly, it may still give patients some relief to get through the day."

The findings were published online May 30 in Regional Anesthesia & Pain Medicine.  

Daily Migraine, Failed Medications

Use of IN ketamine has not been studied for the treatment of chronic, treatment-refractory migraine — although it has been studied in patients with cluster headache and migraine, the investigators note.

Ketamine is not yet approved by the US Food and Drug Administration to treat migraine.

To further explore ketamine's effect in those with chronic, treatment-refractory migraine, the investigators retrospectively analyzed electronic health records of patients at the Jefferson Headache Center who had received IN ketamine for the treatment of migraine between January 2019 and February 2020.

Of 242 patients who had received IN ketamine, Yuan's team followed up with 169 who agreed to be part of the study.

The majority (67%) had daily migraine, and 85% had tried more than three classes of preventive medications for migraine. They currently used a median of two medications, the most common of which was a CGRP monoclonal antibody.

On average, patients used six sprays per day for a median 10 days per month. Median pain relief onset was 52 minutes after dosage.

Almost three quarters of patients reported at least one side effect from the ketamine, most commonly fatigue (22%), double/blurred vision (21%), and confusion/dissociation (21%). These effects were mostly temporary, the researchers report.

The most common reasons for initiating IN ketamine included an incomplete response to prior acute medications (59%), incomplete response to prior preventive medications (31%), and prior benefit from IV ketamine (23%).

Study investigators noted that ketamine has the potential to become addictive and indicated that "clinicians should only consider the use of a potentially addictive medication such as ketamine for significantly disabled patients with migraine."

About half of the participants who used IN ketamine found it "very effective," and 40% found it "somewhat effective." Within the same group, 36% and 43% found the overall impact of IN ketamine on their quality of life was much better and somewhat better, respectively.

Among those still using ketamine during study follow-up, 82% reported that ketamine was very effective.

Compared with other acute headache medications, IN ketamine was considered much better (43%) or somewhat better (30%).

Nearly 75% of participants reported using fewer pain relievers when using IN ketamine.

Yuan said that future research might focus on finding predictors for IN ketamine response or determining the optimal effective and safe dose for the drug in those with chronic, treatment-refractory migraine.  

"We still need a prospective, randomized controlled trial to assess the efficacy and tolerability of intranasal ketamine," he added.

"Impressive Result"

Dr Richard Lipton

Commenting on the findings for Medscape Medical News, Richard Lipton, MD, professor of neurology, psychiatry and behavioral sciences and director of the Montefiore Headache Center at Albert Einstein College of Medicine, New York City, said that "in this refractory population with multiple treatment failures, this is a very impressive, open-label result."

"This real-world data suggests that ketamine is an effective option for people with medically intractable chronic migraine," said Lipton, who was not part of the study. "In these very difficult to treat patients, 65% of those who started on ketamine persisted. Of those who remained on ketamine, 82% found it very effective."

"This study makes me more confident that intranasal ketamine is a helpful treatment option, and I plan to use it more often in the future," he added.

Like Yuan, Lipton highlighted the need for "well-designed placebo-controlled trials" and "rigorous comparative effectiveness studies."

The study was funded by Miles for Migraine. Yuan has received institutional support for serving as an investigator from Teva and AbbVie, and royalties from Cambridge University Press and MedLink. Lipton has received compensation for consultation from Alder/Lumbeck, Axsome, Supernus, Theranica, Upsher-Smith, and Satsuma. He has participated in speaker bureaus for Eli Lilly and Amgen/Novartis and has received institutional support for serving as principal investigator from Teva, GammaCore, and Allergan/AbbVie. He has received payments for authorship or royalties from Demos Medical, Cambridge University Press, and MedLink.

Reg Anesth Pain Med. Published online May 30, 2023. Abstract

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