When new medications are introduced, many of us are eager to try them, hopeful that one will free us from pain. Yet many of us are concerned about the long-term effects and may wait, despite the impact of migraine on our lives. The last few years have seen many advances in migraine-specific treatments. What do we know about their long-term effects?
Robert Cowan, MD, is a leading migraine researcher who has conducted dozens of clinical trials on new medications. He is Professor of Neurology & Neurosciences, Chief, Division of Headache Medicine, at Stanford University School of Medicine, and is both a skeptic and a champion for better patient treatments.
How do new medications make it to market?
Dr. Cowan: In the U.S., the pharmaceutical industry—pharma—does the actual testing of drug efficacy and safety, as opposed to the Food and Drug Administration (FDA). The FDA monitors how pharma tests and develops new drugs, determines if there are general adverse effects, what’s safe dosing, what the side effects are, and whether there are any drug interactions. This process occurs over three distinct phases: Phase 1 determines if there is toxicity; Phase 2 considers the optimum dose; and Phase 3 studies actual patient populations. On average, it takes ten years—and sometimes decades—for a new drug to come to market, and the FDA only approves about one in 5,000 being tested. However, because pharma develops drugs to meet significant medical needs, there can be a great deal of political push to get these new medications approved before we understand their actual long-term impact.
What do recent studies show about Aimovig, the first anti-CGRP medication to be introduced, and therefore the longest in use?
Dr. Cowan: As an anti-CGRP medication, Aimovig is unique in that it binds to the receptor; the others inhibit CGRP from getting to that receptor. Because of the way it functions, it has a months-long half-life (the length of time when its effects continue to work in your body). One side effect of Aimovig for some is constipation. We also know that next to the brain, CGRP is most prominent in the gut, where it’s involved in the continuous process of healing the gut lining. People with Irritable Bowel Syndrome (IBS), a disease that many people with migraine have, can have diarrhea, but some have problems with constipation. If you’re a person who experiences constipation, you should consider a different medication because you don’t want to impact the gut further as well. It is essential that your doctor understands your health history so that you can make decisions about Aimovig, or any medication, based on science and in consideration of your own individual health issues.
What’s the best way for someone to make a determination about the long-term risks of a medication?
Dr. Cowan: If you have particular concerns about a medication in relation to your own health history, I suggest that you wait and see, especially when there isn’t sufficient data. The approach I use with patients is: a) if you’ve tried everything else; b) you’re not getting any better; c) your migraine attacks strongly and negatively impact your life; and d) you would’ve qualified for a clinical trial (meaning you were between the ages of 18 and 65, and don’t have other significant comorbidities), I would say it’s reasonable to try it. If you are not in that general group that’s been studied, but your health is heavily affected, you can still decide to use a medication with the understanding that we don’t yet know the long-term effects. You should always exercise caution, but you also must consider the impact of migraine disease on your life as you make a judgment.
Watch the full interview for answers to:
What kinds of studies are done to test the safety of new medications? How do new medications make it to market?Are there aspects of clinical trials that might ensure the success of a drug but that also could be harmful to patients in the long run?
When is it a good idea to try a medication for which we don’t yet know the long-term risks?
How do patients and clinicians weigh the tolerability and side effects of a medication?How do clinicians find out whether migraine medications cause complications or interact with a patient’s other medical conditions, such as thyroid issues?What have recent studies shown about some of the newer CGRP medications?Have studies been conducted on the long-term effects and possible dependency issues of CGRP medications?Can these findings be applied to other similar drugs?
Why do CGRPs potentially affect the GI tract?
How are side effects of a drug monitored after clinical trials are over and it’s on the market?Which types of migraine medications are contraindicated for patients with heart risk?
When would a CGRP medication be preferable to a triptan?What recommendations are there for people who might be afraid to try some of the newer targeted medications and are instead relying only on their standard ones?
What is the best way to find out if a medication has long-term side effects, and then to determine if the benefit outweighs any risks?
Watch Dr. Cowan’s interview preview hereor order it as part of the Migraine World Summit package from this page.