Ketamine may help patients with refractory migraine pain

In patients with refractory migraines, ketamine may ease migraine pain, at least in the short term, according to study results presented at the Anesthesiology 2017 annual meeting, held in Boston, MA.

“Ketamine may hold promise as a treatment for migraine headaches in patients who have failed other treatments,” said study co-author Eric Schwenk, MD, director of orthopedic anesthesia, Thomas Jefferson University Hospital, Philadelphia, PA. “Our study focused only on short-term relief, but it is encouraging that this treatment might have the potential to help patients long term. Our work provides the basis for future, prospective studies that involve larger numbers of patients.”

Currently, ketamine is used to induce general anesthesia, in lower doses for pain control in many conditions, and with increasing frequency for the treatment of depression. Ketamine is also known as “Special K,” a club drug known for its potent recreational hallucinogenic effects.

Migraine affects an estimated 12% of the United States population, and some patients do not respond to currently available treatments.

Dr. Schwenk and colleagues conducted a retrospective review of 61 patients admitted to Thomas Jefferson Hospital who were treated with ketamine infusions for migraine or other intractable headaches from January 2014 through December 2016.

They found that a 3- to 7-day course of inpatient treatment with ketamine improved migraine intensity in almost 75% of patients. On admission, average migraine headache pain was rated as 7.5, compared with 3.4 upon discharge. Researchers found a statistically significant difference between initial, lowest, and end pain ratings (P < 0.001). The average duration of infusion was 5.1 days, and the lowest pain ratings were achieved on day 4. Patients reached their lowest pain ratings at a mean ketamine rate of 30.8 mg/hr less than the maximum dose (1 mg/kg).

Adverse events were generally mild, and the most common were sedation (51%), blurry vision (38%), and nausea/vomiting (38%). Only one patient requested treatment discontinuation after 1 day of treatment.

According to Dr. Schwenk, a new infusion center will be opened at Thomas Jefferson University Hospital next Fall to treat more patients with headaches using ketamine.

“We hope to expand its use to both more patients and more conditions in the future,” he said.

Dr. Schwenk cautioned, however, that more studies are needed.

“Due to the retrospective nature of the study, we cannot definitively say that ketamine is entirely responsible for the pain relief, but we have provided a basis for additional larger studies to be undertaken,” he concluded.