Monday, June 5, 2023

Intranasal ketamine for refractory chronic migraine

Yuan H, Natekar A, Park J, Lauritsen CG, Viscusi ER, Marmura MJ. Real-world study of intranasal ketamine for use in patients with refractory chronic migraine: a retrospective analysis. Reg Anesth Pain Med. 2023 May 30:rapm-2022-104223. doi: 10.1136/rapm-2022-104223. Epub ahead of print. PMID: 37253638.


Introduction: Subanesthetic ketamine infusion has been used for managing refractory headache in inpatient or outpatient infusion settings. Intranasal ketamine may be an alternative option for outpatient care.

Methods: A retrospective study was conducted at a single tertiary headache center to assess the clinical effectiveness and tolerability of intranasal ketamine in patients with refractory chronic migraine. Candidates who received intranasal ketamine between January 2019 and February 2020 were screened through an electronic medical record query. Manual chart reviews and structured telephone interviews were conducted on obtaining informed consent.

Results: Of 242 subjects screened, 169 (79.9% women) of median (IQR) age 44 (22) years were interviewed. They reported a median (IQR) of 30 (9) monthly headache days and tried 4 (1) classes of preventive medications. Overall, they used 6 (6) sprays per day, with a median (IQR) of spray use of 10 (11) days per month. Intranasal ketamine was reported as 'very effective' in 49.1% and the quality of life was considered 'much better' in 35.5%. At the time of the interview, 65.1% remained current intranasal ketamine users and 74.0% reported at least one adverse event.

Conclusion: In this descriptive study, intranasal ketamine served as an acute treatment for refractory chronic migraine by reducing headache intensity and improving quality of life with relatively tolerable adverse events. Most patients found intranasal ketamine effective and continued to use it despite these adverse events. Given the potential for overuse, it should be reserved for those clearly in need of more effective rescue treatment with appropriate safety precautions. Well-designed prospective placebo-controlled trials are necessary to demonstrate the efficacy and safety of intranasal ketamine in patients with migraine.

Nearly half of patients with refractory chronic migraine interviewed about their use of intranasal ketamine considered the treatment “very effective,” and more than two-thirds said it improved their quality of life. Researchers reported their single-center study results in the journal Regional Anesthesia & Pain Medicine.

“Clinicians should only consider the use of a potentially addictive medication such as ketamine for significantly disabled patients with migraine…,” wrote corresponding author Michael J. Marmura, MD, Thomas Jefferson University Department of Neurology, Philadelphia, Pennsylvania, and study coauthors. “At Jefferson, we have more than 20 years of experience in ketamine infusion for chronic pain and headache and have written guidelines on ketamine use. Understanding the potential risk for outpatient intranasal ketamine use, we have established several strategies/safeguards to ensure patient safety.”

The retrospective study included 169 patients with refractory chronic migraine who received intranasal ketamine at the Jefferson Headache Center between January 2019 and February 2020. Patients in the study experienced a median 30 headache days a month and had tried 4 classes of preventive medications.

“While effective treatment options are limited, as-needed intranasal ketamine seemed to have mitigated acute headache pain intensity and reduced other acute medication use,” researchers reported.

Overall, patients used 6 sprays of intranasal ketamine daily on a median 10 days a month. Some 49.1% of participants deemed the treatment “very effective,” and 39.6% found it “somewhat effective.” Intranasal ketamine led to a “much better” quality of life in 35.5% of patients and “somewhat better” quality of life in 42.6% of patients.

When interviewed for the study, 65.1% of the patients were still using intranasal ketamine. Nearly 75% reported at least one adverse event. Fatigue and double vision/blurred vision were the most common, followed by cognitive adverse events such as confusion/dissociation, vivid dreams, or hallucination.

“These adverse events were usually short-lasting,” researchers wrote, “and patients continued using intranasal ketamine with caution afterwards.”

While further studies are needed to confirm the findings, “this retrospective study suggests that intranasal ketamine may offer a pain-relieving effect with limited morbidity for refractory chronic migraine in the outpatient setting,” the authors advised.

No comments:

Post a Comment