An anti-CGRP injection for migraine prevention
Erenumab
A monthly self-injection that prevents migraine attacks by blocking the CGRP pathway involved in migraine.
What is Erenumab?
Erenumab is an anti-CGRP medicine used to prevent migraine, not to treat an attack once it has started. It is given as a self-injection about once a month and works by blocking the receptor for a protein called CGRP that drives migraine. It is usually offered when several other preventive medicines have not worked.
Education and reference only. This is a plain-language guide to Erenumab — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Erenumab is a monoclonal antibody used to prevent migraine in adults who have frequent attacks. It is given as a self-injection roughly once a month using a pre-filled pen, and is aimed at people whose migraines have not been adequately controlled by several other preventive treatments. It is a preventive medicine, taken regularly to reduce how often migraines happen; it is not used to stop an attack that has already started.
How it works
Erenumab blocks the receptor for a protein called calcitonin gene-related peptide (CGRP), which plays a key role in triggering migraine attacks. By blocking this receptor, it dampens the nerve signalling and blood-vessel changes thought to drive migraine. Over time this reduces how often migraine attacks happen and can make them less severe.
Company & origin
Originated / developed by: Developed by Novartis and Amgen..
Developed jointly by Amgen and Novartis and approved from 2018 as one of the first monoclonal antibodies designed specifically to prevent migraine.
What it treats
Conditions Erenumab is used for
Practical use
How to take Erenumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Give it as a self-injection under the skin, usually about once a month.
- Rotate injection sites (such as thigh, abdomen or upper arm) and follow the training you are given.
- Use it for prevention only; keep using your usual treatments for an actual migraine attack.
- Keep to the regular schedule rather than injecting when a migraine starts.
- Tell your prescriber if you develop troublesome constipation or have a history of raised blood pressure.
Weighing it up
Advantages & disadvantages of Erenumab
Advantages
- Designed specifically to prevent migraine, with a convenient monthly self-injection.
- Can work when several other preventive medicines have failed.
- Generally well tolerated, without the daily-tablet burden of some other preventives.
Disadvantages
- Prevents migraine but does not treat an attack once it has started.
- Given by injection, which some people find off-putting.
- Can cause constipation and a rise in blood pressure that needs monitoring.
Practical use
Good to know
Erenumab is for prevention, so it is taken on a regular schedule rather than when a migraine strikes; you still use your usual acute migraine treatments for individual attacks. It is given as a self-injection, usually monthly, and people are taught how to inject it at home. Injection-site reactions and constipation are the main side effects, and blood pressure should be monitored as it can rise in some people. Its benefit is usually reviewed after a few months to see if it is worth continuing.
Who should not take it / use with caution
- People who are pregnant, planning pregnancy or breastfeeding should discuss it carefully, as experience is limited.
- People with uncontrolled high blood pressure or significant heart or circulation problems need careful assessment.
- Anyone who has had a serious allergic reaction to it.
Monitoring
- Blood pressure before and during treatment.
- Review of migraine frequency after a few months to judge benefit.
- Watch for severe constipation and any signs of an allergic reaction.
Side effects
- Injection-site reactions such as redness, pain or itching.
- Constipation, which can occasionally be severe.
- A rise in blood pressure in some people.
- Muscle spasms or, rarely, allergic reactions.
Key interactions
- Has few known interactions with other medicines, as it is an injected antibody.
- Can be used alongside usual acute migraine treatments for individual attacks.
- Tell your prescriber about all medicines and any blood-pressure treatment you take.
Available as: Pre-filled pen and pre-filled syringe for self-injection.
Answers
Erenumab: frequently asked questions
Does erenumab stop a migraine once it has started?
No. It is a preventive medicine, taken regularly to reduce how often migraines happen. For an actual attack you still use your usual acute migraine treatments.
How often is erenumab given?
It is given as a self-injection roughly once a month using a pre-filled pen, and people are taught how to inject it at home.
Who is erenumab usually offered to?
It is generally offered to people with frequent migraines whose attacks have not been adequately controlled by several other preventive medicines.
What are the main side effects?
The commonest are injection-site reactions and constipation. Blood pressure can also rise in some people, so it is monitored during treatment.
How will I know if it is working?
Its effect on how often migraines happen is usually reviewed after a few months. If it has not helped enough by then, your specialist may stop it.
The wider class
About Anti-CGRP migraine treatments
Erenumab belongs to the anti-cgrp migraine treatments class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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