The CGRP drugs… what you need to know
You’ve likely seen or heard commercials for the new migraine medications, injections that for some people are life-changing. For frequent migraineurs, who haven’t benefitted from first-line treatments, the CGRP antagonists, also referred to as the “CGRP drugs,” are worth considering. Any new class of drugs deserves a closer look, so let’s bust some myths and look at ten important facts about the new migraine meds: the CGRP (calcitonin gene-related peptide) drugs.
How do these work? To keep it simple, think of the CGRP itself as a complicated large molecule made of 3 components and a receptor where it attaches. If the receptor is blocked (Aimovig), then you don’t see headaches. The others (Emgality, Ajovy, and Vyept) bind to the CGRP itself, not the receptor.
What does CGRP do? CGRP is a therapeutic target in migraine because of its role in mediating trigeminocervical pain (pain in the neck and head) and improving inflammation.
Now here are ten facts to help answer the most common questions I hear from patients.
- Choices: There are four options given by injection monthly or every three months. Aimovig (Erenumab) has been around the longest and works slightly differently than the rest. Ajovy (Fremanezumab), Emgality (Galcanezumab), and Vyept (Eptinezumab) bind to the CGRP itself, not the receptor (like Aimovig). They are all monoclonal antibodies (hint, any medication that ends in -mab is).
2. Effectiveness: All of the injection CGRPs have roughly the same efficacy. Aimovig, Emgality, Ajovy, and Vyept all work about the same. About half of people get 50% relief, or better, 10-15% get an excellent response (almost no headaches), then some get zero response. In general, what you see at two months as far as response, is what you’re going to see at six months, etc.
3. What about the pill forms, not injections? You’ll see commercials for Nurtec and Ubrelvy but the injection CGRP meds listed above work better than the orals. So, this article isn’t talking about the oral options here called “Gepants.”
4. Do they cause depression and anxiety? While uncommon, there are reports of depression and anxiety with the CGRP injections. These medications don’t cross the blood-brain barrier, but because some areas are not “protected,” there may be slight penetration to the brain, which may be the culprit for anxiety/depression side effects.
5. The CGRPs can make migraines worse. This is true for a small number of people. For 3-5 days after injection, headaches may be worse, then they improve. If headaches are worse for 2-3 weeks after the injection, you should not use the CGRP medications.
6. In most people, there are little to no side effects. The CGRP monoclonal antibodies are generally well tolerated in clinical trials. Injection site reactions were the most commonly observed adverse effects.
7. Common side effects. Constipation and high blood pressure have been observed, more commonly with Aimovig. Reports of weight gain and bloating exist but so do reports of weight loss. The CGRP medications inhibit hair growth in some patients, and hair loss may occur in 3-5% of folks taking them.
8. Cost, yikes. Getting them paid for is an issue, and the injection CGRPs are about 600 dollars per month. An appeal from your doctor may work, and when insurance picks a certain CGRP —go with what insurance allows.
9. They don’t touch your liver and kidneys. A cool fact about the injection CGRPs is your liver or kidneys do NOT clear them. Instead, they are removed by the lymphatic system. Because of this, there are no significant drug interactions with the other migraine medications (triptans, SSRIs, and beta-blockers).
10. Don’t use during pregnancy or while breastfeeding: Simply put, the potential adverse effects of the CGRP monoclonal antibodies related to pregnancy or breastfeeding are unknown. As a result, they are not indicated for use if you are pregnant or nursing.
Take home message. While we need to get to know them better, the calcitonin gene-related peptide monoclonal antibodies, the CGRP meds, have been very effective for many chronic migraineurs who previously failed the standard treatments.
I am a Clinical Associate Professor of Medicine at the Keck School of Medicine of USC and a board-certified Internal Medicine physician. For 20 years I’ve had an active private practice in general internal medicine currently at The Doctors of USC Beverly Hills. I am lucky to spend part of my time as the attending physician for medical students and residents during their rotations at LAC+USC Medical Center. I’ve been a medical advisor on leading health social networking sites including Dailystrength.org and Sharecare and currently serve as the medical advisor and blogger for GoodRx.com, a prescription drug price comparison website, and GoodRx care powered by Hey Doctor.
My philosophy of care centers around seeing things we can see coming, and nailing them head-on. I appreciate the idea of sharing power and responsibility for the choices one makes for prevention, treatment, and investigation into medical problems. My hope is to write blog posts to empower patients to navigate their own health by laying out the ways that medicine can guide you with strategies to investigate, prevent, and treat some common medical issues, big and small.
I have appeared on The Doctors, Fox Sports West, The Ricki Lake Show, as well as many local news outlets and have been featured in numerous online and print publications. I am a fellow of the American College of Physicians and honored to be named “Top Doctor” in Los Angeles and Pasadena Magazine for years.