By Alan Mozes HealthDay Reporter
THURSDAY, May 26, 2022 (HealthDay News)
That’s the takeaway from a new study that examined the effectiveness of lidocaine infusion treatment — a much debated therapy that requires a hospital stay — as a means to address “refractory chronic migraines” (rCM).
Those first-line treatments include standard pain killers and beta blockers; corticosteroids; antidepressants; anti-convulsants; calcium blockers; Botox injections, and/or noninvasive electrical stimulation.
“Lidocaine is a local anesthetic — a numbing medicine — but also reduces inflammation in studies,” said study author Dr. Eric Schwenk, director of orthopedic anesthesia at the Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia.
Between 1% and 2% of the population get the chronic migraine headaches.
The researchers looked at hospital records for just over 600 patients, most of them women (average age: 46).
All had been admitted to a Philadelphia hospital between 2017 and 2020 for lidocaine infusion treatment, typically for five to seven days.
Upon admission, lidocaine infusions were initially started at 1 mg per minute, then increased up to 4 mg per minute. (Other IV medications were administered at the same time, including ketorolac — a nonsteroidal anti-inflammatory drug — and the corticosteroid methylprednisolone.)
At a follow-up appointment 25 to 65 days later, patients reported that on average, they had headaches on 23 of the last 30 days — four fewer than before treatment.
“For them, lidocaine may help break the cycle of continuous pain,” he said.
Researchers also noted that about 88% of patients reported some degree of pain relief, with pain intensity plummeting from a self-reported score level of 7 at intake, down to 1 at discharge, out of 10.
“But lidocaine was well tolerated overall,” he noted. “No serious adverse events occurred.”
On the downside, however, an average hospital stay of more than five days may not be feasible for many patients, Schwenk noted.
It also remains unclear just how lidocaine works to alleviate rCM. “Its mechanism of action in migraine is unknown,” he said.
Schwenk and his colleagues also noted that because of the nature of their look-back analysis, the study could not definitively prove that lidocaine was the direct cause of a reduction in rCM frequency. A similar study earlier this year also evaluated the infusion therapy.
Dr. Teshamae Monteith, a fellow with the American Academy of Neurology, and chief of the headache division at the University of Miami’s Miller School of Medicine, reviewed the new findings.
She said she was “not surprised by the benefits of lidocaine,” having used the treatment often for patients with these hard-to-treat headache disorders.
Monteith noted that the infusion therapy is already in use in many headache centers and is “generally considered safe with side effects that are transient.”
As to the source of the benefit, she said the therapy likely works by interrupting a major pain-signaling connection to the brain, a neural route known as the trigeminovascular pathway.
Nevertheless, Monteith emphasized the need for further study “to determine which patients are best candidates for intravenous lidocaine [and] long-term follow-up studies post-discharge.”
The findings were published May 23 in the journal Regional Anesthesia & Pain Medicine.
SOURCES: Eric Schwenk, MD, associate professor and director, orthopedic anesthesia, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia; Teshamae Monteith, MD, fellow, American Academy of Neurology, and associate professor, clinical neurology, and chief, headache division, University of Miami Miller School of Medicine; Regional Anesthesia & Pain Medicine, May 23, 2022
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