For a significant percentage of the 39 million Americans who suffer from migraines, standard treatments have provided little relief. Now a new class of medicines shows promise for reducing the frequency and severity of these debilitating headaches.
Three new preventive medicines approved this year by the U.S. Food and Drug Administration work by blocking a chemical in the brain that triggers migraine pain. These drugs are called calcitonin gene-related peptide (CGRP) antagonists, and go by the brand names Emgality, Aimovig and Ajovy.
During migraine attacks, multiple molecules are released at the trigeminal nerve endings onto the dural blood vessels on the surface of the brain, says Anna Morenkova, MD, UCI Health neurologist and assistant professor of the UCI School of Medicine’s Department of Neurology. One of those is CGRP.
Once CGRP is released, blood vessels dilate, causing plasma leakage and inflammation that in turn irritates trigeminal nerve endings, sending pain stimuli to the brain’s pain centers.
“Work has been continuing for years to find something to block CGRP,” Morenkova says. “Now, finally something has been discovered to make it inactive.”
What causes migraines is still unknown
Migraines are debilitating headaches lasting anywhere from four to 72 hours and are characterized by moderate to severe throbbing or pulsing pain. They’re often accompanied by nausea and vomiting, as well as heightened sensitivity to light and sound.
While sufferers often know when one is coming on, doctors still don’t know why they strike.
“Migraine is not just a headache, it is a benign brain disorder,” says Morenkova. “We don’t know where in the brain a migraine attack starts or what causes it.”
Neurologists do, however, understand the pathways that pain travels in the brain and that nerves are activated to create pain. Treatments typically have been aimed at reducing inflammation around the blood vessels in the brain and the dura, the membrane that encases the brain and spinal cord.
Timing of treatment is critical
To be effective, though, those treatments need to start as soon as possible after the onset of symptoms.
Pain relievers such as aspirin, ibuprofen, acetaminophen and a range of triptans, which act on serotonin receptors to cause blood vessel constriction, are standard treatments for migraine pain control.
A range of additional medicines are also effective in reducing the frequency of migraine attacks. They include:
- Seizure medicines
- Blood pressure medicines
“If we’re delayed in taking away the pain, the pain information continues to be transmitted to the brain,” Morenkova says. “Our goal is reduce the number of migraine attacks so that we can use pain medications less frequently.”
New medicines given by injection
The newly approved drugs that target CPRG are given via monthly injections and studies show that many patients experienced a reduction in both the number and intensity of migraine attacks.
Side-effects, which studies indicate are minimal, include injection-site infections, fatigue or flu-like symptoms and constipation. These drugs may also take the place of others not tolerated by some patients because of more challenging side effects.
“Studies show that the frequency and severity of headaches is reduced with these drugs,” Morenkova says. “We use them prophylactically.”
Many of her patients have experienced a dramatic reduction in headache frequency. Others saw mild to moderate improvement, while some, unfortunately had no improvement.
Pharmaceutical companies are continuing to work on using CGRP-antagonists to treat pain once a migraine attack is underway.
Tips for relieving migraine pain on your own
The brains of people susceptible to migraines seem to be highly sensitive to abrupt change, so things like changes in weather, hunger, not enough or too much sleep, hormonal changes or stress are common triggers. Some triggers can be avoided, but many cannot. Preventive medications seem to reduce the brain’s vulnerability to these migraine triggers.
Once an attack is underway, however, Morenkova says sufferers may be able to ease its severity by:
- Resting and avoiding irritating light, noise and smells
- Applying heat or cold to the base of the skull or forehead
- Massaging the neck and temples
- Immersing feet up to the ankles in very hot water for 5 to 10 minutes