On this page
- What is this information about?
- Why have I been given this information?
- How does erenumab work?
- How do I take erenumab and get my supplies?
- What must I do as soon as I have taken my first dose of erenumab?
- How long will I take erenumab for to start with?
- Must I keep a headache diary while I am on my trial of erenumab?
- How will you know whether erenumab is working for me and if I should continue to take it after my three month trial?
- Might my migraine improve further if continue to take erenumab beyond my three-month trial?
- What happens if erenumab treatment has not worked well for me?
- What are the side effects?
- Which health conditions that I may have had must I tell my consultant or the headache nursing team about?
- Who should I contact if I have any questions or concerns about erenumab treatment for migraine after I have read this information?
What is this information about?
This information is about a medicine called erenumab. The brand name of this medicine is Aimovig.
If you have chronic or episodic migraine, erenumab may help you to have migraines less often and make those that you do have less severe.

Your migraine is called ‘chronic migraine’ when you have at least 15 headache days a month and at least eight of these are migraine days.
Your migraine is called ‘episodic migraine’ if you get four to seven migraines a month.
This information explains:
- how erenumab works
- how you take and get supplies of erenumab
- who can take it
- what the side effects are
- what benefit you may get from taking it
- which things mean you should not take it (what erenumab’s ‘cautions’ are).
Why have I been given this information?
You have been given this information because your specialist (Consultant Neurologist or Specialist Nurse) has prescribed erenumab for you. This is because the medicines that you have been given to treat your migraines so far have not worked well for you.
Reading this information will help you to know what to expect from your treatment and to be safe while you are taking it.
How does erenumab work?
Erenumab is one of a type of drugs called CGRP inhibitors. They are designed to reduce the release of a substance called Calcitonin Gene Related Peptide (CRGP) into your body when you have a migraine. Too much CGRP is thought to be released during a migraine attack, and this may be why you feel pain when you are having a migraine.
Erenumab is a ‘preventive’ medicine. Taken regularly it can help to reduce how often you get migraines and how severe they are.
How do I take erenumab and get my supplies?
- Your doses of erenumab come in pre-filled syringes. This means that you do not have to measure your dose or fill the syringe
- You will give yourself the injections at home
- You must give yourself one injection every 28 days (four weeks)
- You will usually give yourself the injection into your tummy or your thigh. This is not likely to hurt very much.
Your syringes will be delivered to you from a healthcare company which is not part of University Hospitals Sussex or the NHS.
When you receive them, do put them in your fridge and store them there until you give yourself your injection.
The company that delivers your erenumab will contact you to arrange for a nurse to show you how to do your injections if you would like this.
If erenumab works for you, and your doctor or specialist nurse decide to continue to prescribe it for you, they will tell the company who will deliver further batches.
What must I do as soon as I have taken my first dose of erenumab?
Do contact your Headache Nurse Specialist as soon as you have had your first dose. This is because they must arrange a phone appointment for you. This has to be soon after you have had your third dose, and they need to know when this should be.
How long will I take erenumab for to start with?
To start with you will have a three month ‘trial’ prescription of erenumab.
Must I keep a headache diary while I am on my trial of erenumab?
Yes, do keep a headache diary. Mark each day that you have a migraine or headache. For each day that you mark, note a pain score and whether you needed to take any other medicine (painkillers) to control your pain.
We will give you a headache diary to fill in. If you do not have one, please contact your specialist nurse.
It is important that you keep your headache diary so that we know whether erenumab is working for you and if you should keep taking it.
How will you know whether erenumab is working for me and if I should continue to take it after my three month trial?
We must follow guidelines from NICE (the National Institute for Health and Care Excellence). These say how much of an improvement in your migraine there must be during your trial for us to continue to prescribe it for you:
- for episodic migraine you must have 50% (half) as many migraines as you did before you were taking erenumab
- for chronic migraine you must have 30% (just over a third) less migraines as you did before you were taking erenumab.
Shortly after you have taken the third (last) dose of erenumab of your three month trial you will have a phone appointment with us. We will talk with you about how many migraines you have had and how you feel taking erenumab has been for you.
If erenumab is right for you and your migraine has improved enough we will arrange for a further prescription to be sent to the delivery company. Your erenumab will be delivered to you as before.
Be aware
We cannot issue another prescription for erenumab, and it will not be delivered to you, unless you have had your phone appointment, and your migraines have improved enough.
Might my migraine improve further if continue to take erenumab beyond my three-month trial?
Yes, the benefits of erenumab can build up over six months so your migraine may continue to get better after your trial.
What happens if erenumab treatment has not worked well for me?
If erenumab did not work as well for you during your trial as the NICE guidance says it must, it is very likely that your prescription will be stopped.
The headache nursing team will speak with your consultant who will try to find a treatment that will work better for you. You will still be under the care of the Neurology department and do not have to re-join the waiting list for further treatment.
What are the side effects?
Be aware
The erenumab syringe contains latex. Do not use it if you are allergic to latex. Tell the Headache team if you have a latex allergy and they will talk with you about other options.
Like most medicines erenumab can have side effects. The most usual side effects include:
- constipation (hard, dry poos and pooing less than 3 times a week). Around 1 in 10 people who take erenumab may get constipation. Most people can manage this by changing their diet (what they eat and drink). You should not have erenumab if you have had a lot of problems with constipation in the past.
- swelling at the place on your body where you have the injection
- flu-like symptoms
- muscle spasms
- mildly raised blood pressure.
Be aware
As erenumab and other similar medicines (CRGP inhibitors) can raise your blood pressure slightly, do check your blood pressure around once a month while you are taking it.
Less usual side effects include:
- alopecia (hair loss)
- breathing difficulties
If you are concerned about possible side effects do speak to a healthcare professional.
Which health conditions that I may have had must I tell my consultant or the headache nursing team about?
You must not take erenumab if you are pregnant or breastfeeding. Some health conditions mean that taking erenumab might not be safe for you.
Let your consultant or headache nursing team know if you have ever experienced or experience any of the following:
- high blood pressure (blood pressure over 150mmHg systolic)
- heart attack
- stroke
- DVT
- transient ischemic attack (TIA)
- unstable angina
- a disease or condition which has damaged your liver or kidneys, so they do not work as well
- bowel disease that makes you more likely to be constipated
or if you plan pregnancy soon or are breastfeeding.
Who should I contact if I have any questions or concerns about erenumab treatment for migraine after I have read this information?
Email: [email protected]
Our office is staffed from Monday to Friday.
This leaflet is intended for patients receiving care in Brighton, Haywards Heath, Worthing and Chichester.
The information in this leaflet is for guidance purposes only and is in no way intended to replace professional clinical advice by a qualified practitioner.