TeachableMedicalNews article 07312019
Teachable moment in classrooms:
- general senses chapter – unconventional types of pain
- general senses chapter – pharmaceuticals in of pain control
- immune system chapter – antibodies as pharmaceuticals
Can an injectable treatment work for migraines?
The news item: New injectable preventions and treatments for migraine were in the news recently. One of them is Aimovig (erenumab):
FDA approves new drug that stops chronic migraines
The FDA approves, Erenumab, a new migraine treatment, that blocks chronic and disabling headaches, without causing many side effects.
The article mentions migraine statistics, the calcitonin gene related peptide (CGRP) as the culprit in migraines, and that the new drug is an antibody.
So, Why Do I Care?? There are about 39 million migraine sufferers in the USA. Among them about 4 million who suffers from chronic migraine lasting for 10-14 days. The impact of migraine is more than the personal suffering; the US economy loses $36 billion yearly because of lost productivity linked to migraine. While occasional migraine can be successfully treated with common medications, the chronic migraine sufferers don’t have a reliable treatment.
Plain English, Please!!! First, let’s talk about migraine. Migraine is a disorder of the central nervous system, and during a migraine attack the malfunctioning nervous system creates pain in the head area, visual disturbances (auras), and sometimes dizziness and nausea. So, that’s why this disorder is so debilitating.
Second, let’s talk about pain, this warning signal of our nervous system. We sense pain when tissue damage triggers nerve impulses in the nerve cells of the damaged body area, and those neurons conduct the nerve impulse to the brain. Everyday pain killer drugs either block the action of chemical released during tissue damage, or they block the movement of the nerve impulse to the brain.
Third, let’s talk about this new treatment for migraine. Because migraine is not the result of tissue damage, common pain killers don’t work on chronic migraine pain. Many years of research identified a chemical that trigger migraine pain; that chemical is called calcitonin gene related peptide (CGRP). Migraine happens when CGRP reaches receptors on the neurons in the brain. The receptor is like a wide receiver in football; the peptide has to be caught by the receptor to start migraine pain, like the wide receiver has to catch the football for a touchdown. So, how can you block the action of that migraine-triggering peptide? Imagine a football game where the arms of the wide receiver are duct taped to his body. The drug erenumab does that to the receptor, so the CGRP peptide can not be caught by the receptor, so there is no more triggering of pain. The duct tape, erenumab, can target CGRP receptors only, because erenumab is a modified antibody, a protein made by immune system cells to specifically target invaders in the body. As antibodies are proteins, they can not be taken orally, but have to be injected.