Neurology
Anti-CGRP migraine treatments
CGRP monoclonal antibodies and gepants — Modern, targeted treatments that prevent (and in some cases treat) migraine by blocking the CGRP pathway.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
Quick answer
What is Anti-CGRP migraine treatments?
Anti-CGRP treatments are modern migraine medicines that block a nerve signalling molecule (CGRP) central to migraine. They include regular injections that prevent migraine and oral "gepant" tablets that can treat or prevent attacks, used mainly when other treatments have not worked.
- How it works: CGRP is a molecule released around the brain's blood vessels and nerves during a migraine that drives the pain and inflammation.
- In practice: In practice anti-CGRP treatments are a modern, targeted class that has transformed migraine care for people with frequent or hard-to-treat migraine, used when several standard preventives have failed.
What it is
Anti-CGRP treatments are modern migraine medicines that block a nerve signalling molecule (CGRP) central to migraine. They include regular injections that prevent migraine and oral "gepant" tablets that can treat or prevent attacks, used mainly when other treatments have not worked.
How it works
CGRP is a molecule released around the brain's blood vessels and nerves during a migraine that drives the pain and inflammation. These treatments either mop up CGRP or block its receptor, interrupting that pathway — so migraines become less frequent or an attack is stopped, with a much more targeted action than older, general-purpose preventives.
In practice
In practice anti-CGRP treatments are a modern, targeted class that has transformed migraine care for people with frequent or hard-to-treat migraine, used when several standard preventives have failed. They come in two forms: monthly or quarterly injections (monoclonal antibodies such as erenumab and fremanezumab) that prevent migraine, and oral "gepants" (such as rimegepant) that can treat an attack and, for some, also prevent. Their appeal is that they are specifically designed for migraine and are generally well tolerated, without the weight gain, drowsiness or broad side effects of older preventives. The practical themes are: they are specialist-initiated and usually require a documented number of monthly migraine days and prior failed preventives before funding; the injectable antibodies are self-administered with mainly injection-site reactions and occasional constipation (notably with erenumab); and response is reviewed after a few months, continuing only if migraine days have meaningfully fallen. They are avoided or used cautiously in pregnancy and are still being studied in people with significant cardiovascular disease, since CGRP also has a role in blood vessels. They complement, rather than replace, acute treatments and lifestyle/trigger management.
Examples
Practical use
How to take it & use it well
- These treatments work against a natural substance called CGRP that drives migraine; some are injections you give yourself to prevent attacks, and some are tablets used to treat or prevent them.
- If you have a self-injected preventer, you will be shown how to give it into the skin of the thigh, tummy or upper arm, and to rotate the spot each time to spare the skin.
- If you have a tablet that works the same way, take it as prescribed, either to stop an attack as it starts or regularly to prevent them, as your specialist has advised.
- Keep a headache diary of how many days you get migraine and how bad they are, as this is the best way to see whether the treatment is truly helping.
- Give it time and attend your review, as these treatments are usually judged over a couple of months before deciding whether to carry on.
- Do not stop suddenly without advice, and tell your team about side effects such as constipation or injection-site reactions rather than just giving up on it.
Common uses
- Prevention of frequent or treatment-resistant migraine
- Acute treatment of migraine attacks (some gepants)
- When several standard preventives have failed or are unsuitable
Monitoring
- Migraine-day frequency (a headache diary) to judge response
- Injection-site reactions, constipation and blood pressure where relevant
- Continued benefit at review points
Weighing it up
Advantages & disadvantages
Advantages
- They are designed specifically to target migraine, rather than being borrowed from other conditions like many older preventers.
- They are generally well tolerated, with far fewer of the bothersome effects seen with some traditional preventives.
- The injected preventers are taken only now and then, which is convenient compared with daily tablets.
- Some forms can be used both to prevent migraine and to treat an attack as it happens.
- For people who have tried several other preventers without success, they offer a real new option.
Disadvantages
- They are specialist treatments, usually only started after several other preventives have been tried and have not worked.
- The injected forms can cause redness, itching or soreness where the needle goes in.
- Constipation can occur, particularly with one of the injected treatments, and is sometimes troublesome.
- They do not work for everyone, so a careful review is needed to see whether they are worth continuing.
- There is caution about using them in pregnancy and in people with certain heart or circulation problems.
Key safety principles
What to watch for
- Specialist-initiated, usually after other preventives have failed; response is reviewed after a few months and continued only if migraine days fall meaningfully.
- Generally well tolerated — mainly injection-site reactions and, with some, constipation; avoided or used cautiously in pregnancy.
- CGRP also affects blood vessels — used with caution and still being studied in significant cardiovascular disease.
Key interactions
What to avoid or check alongside
- They are generally free of the many drug clashes seen with older migraine preventers, which is one of their attractions.
- Constipation can be worse if you also take other medicines that slow the bowel, such as some strong painkillers, so mention these to your team.
- They are used cautiously in people with heart or circulation disease, so your team will want to know your full history.
- Tell your specialist if you are pregnant, planning pregnancy or breastfeeding, as caution is advised and the plan may change.
- Keep your team informed of all your other migraine treatments, as these preventers are meant to work alongside, not replace, sensible attack treatment.
Patient & carer advice
- Keep a headache diary so we can see whether your migraine days are really falling
- The injections are usually given monthly or less often, and most side effects are mild
- These work alongside your attack treatments and trigger management, not instead of them
Answers
Anti-CGRP migraine treatments: frequently asked questions
How do anti-CGRP migraine treatments work?
They block the action of a natural substance called CGRP, which plays a key part in migraine. Some are injections you give yourself to prevent attacks, and some are tablets that can stop an attack starting or be taken regularly to prevent them. Because they target migraine directly, they are often better tolerated than older preventers.
Who can have these migraine treatments?
They are specialist treatments, usually offered after several other preventive medicines have been tried and have not worked well enough or were not tolerated. A headache specialist decides whether they are suitable, sets up a trial, and reviews how well they work before deciding whether to continue.
Why should I keep a headache diary?
A diary of how many days you get migraine, how severe they are and how much medicine you use is the clearest way to tell whether the treatment is helping. Your specialist uses it at review to decide whether to carry on, so keeping it accurately really matters to getting the right decision.
What side effects might I notice?
These treatments are generally well tolerated. The injected forms can cause redness, itching or soreness where the needle goes in, and constipation can occur, especially with one of them. Tell your team about any side effects rather than stopping on your own, as they can advise and help you decide whether to continue.
Are they safe in pregnancy?
Caution is advised, and they are not usually recommended in pregnancy, as experience is still limited. If you are pregnant, planning a pregnancy or breastfeeding, tell your specialist before starting or continuing, so your migraine plan can be adjusted to something better suited to your situation.
Authoritative sources
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