What Is CGRP?
CGRP (Calcitonin Gene-Related Peptide) is a protein present in the brain and nervous system and is more commonly present in the sensory nerves supplying the head and neck. It is a vasodilator and is produced in both peripheral and central neurons. It affects the trigeminal nerve, which has a role in pain transmission and sensitivities to touch and temperature to the tissues and blood vessels. There are different forms of CGRP in various body parts, performing different actions.
CGRP plays a significant role in inducing migraines. Research has shown elevated levels of CGRP in the saliva, plasma, and tear fluid of a few people with spontaneous migraine. CGRP also plays an effective role in appetite suppressants, increased heart rate, temperature homeostasis, gastric acid secretion, and the release of pituitary hormones.
What Are CGRP Inhibitors?
CGRP inhibitors are medications that block the CGRP’s effects. In many cases of migraine, CGRP is considered a main causative agent in the induction of migraine attacks. Therefore, CGRP inhibitors are used in the management of migraines. CGRP inhibitors were the first drugs developed to prevent migraines. All other drugs used before for migraine management were originally developed for other medical conditions, such as high blood pressure, and later, by chance, were found effective for migraine management. Two types of CGRP inhibitors are CGRP receptor antagonists (gepants) and monoclonal antibodies.
CGRP Receptor Antagonists - CGRP receptor antagonists (Gepants) are small molecule drugs that block the CGRP receptor. These drugs are effective at both preventing and relieving migraines. Gepants are more effective when migraines are treated in their milder stages. These drug's effects are longer-lasting when compared to other anti-migraine medications (triptans), making the chance of recurrence very less. Compared to monoclonal antibodies, gepants act rapidly as they penetrate directly into the brain. However, the interactions and liver damage is more when they are metabolized in the liver. Ubrelvy (Ubrogepant), Nurtec ODT (Rimegepant sulfate), Qulipta (Atogepant), and Zavzpret (Zavegepant) are the approved gepants that are currently available in the markets.
Monoclonal Antibodies - They are drugs that target either CGRP or its receptor. Therefore, these drugs are used for the management of migraines. Monoclonal antibodies are identical proteins used to target one substance in the body. When compared to genpets, monoclonal antibodies are large molecules, so they take longer to start working. This drug is administered by injection subcutaneously (under the skin), so it avoids degradation by the stomach. Also, when compared to genpets they tend to have few drug interactions, and they do not cause liver or kidney damage. However, they can cause side effects like upper respiratory tract infections, constipation, nausea, pain at the site of injection, and fatigue. Aimovig (Erenumab-aooe), Ajovy (Fremanezumab), Emgality (Galcanezumab-gnlm), and Vyepti (Eptinezumab-jjmr), are the approved monoclonal antibody CGRP inhibitors.
What Are the Advantages of CGRP Inhibitors for Migraine?
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CGRP medications are a class of preventive drugs specifically designed for treating migraines. Prior to their development, migraine prevention primarily relied on repurposed medications intended for different medical conditions, such as hypertension and depression, which will also act to reduce migraine.
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For individuals who find conventional migraine treatments ineffective, CGRP migraine therapies have proven advantageous. Research indicates that approximately one-third of individuals undergoing CGRP treatment experienced a 50 percent reduction in migraines and a diminished frequency of attacks. Another study suggests that half of migraine sufferers saw up to a 75 percent improvement.
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CGRP medications exhibit a faster onset of action compared to other acute migraine treatments.
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Determining the effectiveness of conventional migraine drugs usually takes a few months, but in the case of individuals utilizing CGRP inhibitors for migraine treatment or prevention shows rapid results.
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CGRP inhibitors tend to have fewer side effects when compared to older medications.
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People who use CGRP medications receive either monthly or quarterly doses this will help to reduce the likelihood of missed doses.
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Unlike some migraine medications that may lose effectiveness over prolonged use, CGRP has not shown any decline in its ability to treat migraines.
What Are the Side Effects of CGRP Inhibitors?
CGRP inhibitors are generally well-tolerated and have few side effects. A few mild to moderate side effects from CGRP inhibitors have been reported, including the following:
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Nausea.
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Vomiting.
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Back pain.
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Visual problems.
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Headache.
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Upper respiratory infections.
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Tingling or pins and needles sensations.
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Liver toxicity.
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Fatigue.
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Joint stiffness.
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Pain at the site of injection.
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Hair loss.
When Are CGRP Inhibitors Recommended?
CGRP inhibitors are indicated for people with episodic and chronic migraines. This drug is safe as there is no proven adverse reaction to this drug. However, as it is a new drug more long-term data is needed to prove its efficiency. So it is necessary to consult a healthcare professional before taking it.
For individuals with episodic migraines CGRP inhibitors are very effective and the studies show that almost 88 percent of people had fewer headache days. Also, it is better at relieving the intensity of migraine than conventional migraine medications. This drug is considered if people do not get headache relief from conventional migraine medications or have a lot of side effects from conventional migraine medications.
What Are the Risks of CGRP Inhibitors?
As CGRP inhibitors are new drugs, all the effects of CGRP treatments are not yet known. More studies are required to understand the potential risks of these medications. While CGRP plays a role in migraine, it can also influence the risk of heart conditions. CGRP is a vasodilator, meaning it can dilate blood vessels to help balance blood pressure, so if this action is blocked, it could affect blood pressure and heart health. Also, there are limited resources about whether CGRP inhibitors can be taken during pregnancy or not; healthcare professionals may not suggest their use during pregnancy.
Conclusion
CGRP inhibitors are a new type of treatment for migraine. It offers a targeted and effective approach to managing and preventing migraine attacks. CGRP helps manage chronic and recurrent migraines with minimal or no side effects. However, as it is a new medication, more studies are required about its effects. These medications provide hope for improved life quality for individuals who suffer from this debilitating condition.
