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Erenumab for the prevention of episodic and chronic migraine (autoinjector pen)

Patient information A-Z

Who is the leaflet for? What is its aim?

You have been prescribed erenumab (known as Aimovig) to help treat your migraine. This leaflet will tell you about erenumab and how to use it. You should keep it to hand for easy reference.

About erenumab

Erenumab is from a new group of medicines designed to bind to a substance called calcitonin gene-related peptide (CGRP) and block its ability to act and interact with its receptor. These medicines are known as monoclonal antibodies (mAbs). They are designed as antibodies that recognise and bind to the CGRP but have no other known interference with the immune system. This group of medicines has arisen from recent advances in our understanding of migraine and is the first class of preventative medicine designed specifically for migraine.

It has been demonstrated that during a migraine attack CGRP levels rise. CGRP can be temporarily blocked by migraine-specific pain relief medications (medications specifically from the triptan group, for example sumatriptan, rizatriptan, zolmitriptan, eletriptan). This is thought to be how they produce the painkiller effects. Unlike the triptans, which work in the short term, the CGRP mAbs are able to do this effectively on a long-term basis.

Clinical trials have shown that CGRP mAbs can be a very effective treatment in some patients with migraine, with 30% to 50% of patients reporting reduction in their migraine days by at least 50%.

This medicine will be considered by your hospital doctor if you have:

  • chronic migraine (more than fifteen headache days per month, of which the headaches on at least eight days have migrainous features, and this has been the case for at least three months)
  • episodic migraine (with four or more disabling migraine days per month, and this has been the case for at least three months)
  • addressed any pain relief overuse (which should be considered if there is regular acute painkiller medication taken on more than ten days per month for several months)
  • tried at least three preventative drug treatments from different drug groups (and these have been deemed sufficient trials) and they have been ineffective
  • considered a trial of cranial botulinum (Botox) treatment in the case of chronic migraine – this is an alternative injectable treatment for chronic migraine, with 31 to 39 injections of Botox given to specific sites in the face/ head/ neck/ shoulders and a minimum of two treatments given three months apart

Medical considerations regarding suitability for treatment

Erenumab must not be used if you have had a previous serious adverse reaction to it which was thought to be due to an allergy (called hypersensitivity) to the active drug or to any of the product contents. Furthermore, if you have had a significant allergic/ hypersensitivity response to one of the other CGRP mAbs then you must make sure your prescribing neurologist is aware of this, as erenumab may not be the right treatment for you.

The clinical trials in patients taking erenumab did not include patients who had known significant heart (specifically heart attacks, angina, or a previous coronary artery bypass), brain (specifically stroke), or other diseases related to the blood vessels (leg clot or deep vein thrombosis, lung clot or pulmonary embolus). Please discuss this with your prescribing neurologist as the relative safety of this drug is uncertain and will need careful consideration. High blood pressure has emerged in patients taking erenumab and if you have pre-existing high blood pressure, or this has been a previous concern, please alert your prescribing neurologist as this may need to be managed separately before you embark on this treatment.

Will this interact with my other medications?

No formal clinical studies have been done looking to see if erenumab interacts with other medications. However, based on the knowledge of this drug, no interactions are expected and we do not suggest stopping other oral medications. If you are taking another monoclonal antibody for a different medical condition, please make sure your prescribing neurologist is aware of this as they may recommend that the timing of the administration of erenumab is separated from that of your other treatment.

Method of delivery and dosage

The medication comes as an autoinjector pen containing 140mg of erenumab and is suitable for subcutaneous (just under the skin) self-delivery. You will administer one injection (140mg) every four weeks for three months, with a follow-up appointment after this to determine whether further treatment is indicated.

Dosing schedule

Day and date started: ..................................
No. of pens Total dose
Month 1 No. of pens 1 Total dose 140mg
Month 2 No. of pens 1 Total dose 140mg
Month 3 No. of pens 1 Total dose 140mg

After three months, your neurology team will need to review you, together with your headache diary, and decide whether further treatment is advised. Further monthly 140mg erenumab injections may be recommended.

Travelling with the medication

If you are going away on holiday, or travelling for work, then you should be able to take the medication with you, provided you can transport it appropriately at the correct temperature. The temperature during transport is important, and taking it with you is allowed providing you ensure that you can either:

a) keep it chilled at a temperature of 2°C to 8°C in a cool bag with a cold pack. This should be for the shortest time possible (must be less than 24 hours). You must put it directly in the fridge at your destination; or

b) keep it at a temperature lower than 25°C, during which time it can be kept unrefrigerated, but must be used within 14 days. (If this time is exceeded the medication should be discarded).

Taking the medication out of the fridge must not be done repeatedly and should, in normal circumstances, only be done once, at the time you are due to administer it. If, due to travelling, it is not possible to guarantee that you will meet the recommendations above, we suggest that you delay your treatment until you are back home and then take it as close to your due date as feasible.

Storage and handling

  • Store in the refrigerator between 2°C and 8°C.
  • Protect from light until time of administration and keep within the original outer container/ box.
  • Do not freeze. Discard if this occurs.
  • Do not shake the pen. Discard if this occurs.

Method of administration

You will be provided with a supply of erenumab/ Aimovig autoinjector pens and will receive training from a healthcare specialist on administration before starting treatment.

Before injection:

  1. Remove erenumab/ Aimovig from the refrigerator. Immediately return any remaining autoinjector pens to the original container/ box in the refrigerator. Allow the autoinjector pen you will be using to reach room temperature before administration. This will take approximately 30 minutes. Once taken out of the refrigerator and allowed to reach room temperature, the autoinjector pen/s must not be returned to the refrigerator.
  2. DO NOT attempt to heat the pen to bring it to room temperature quickly.

DO NOT leave the autoinjector pen in direct sunlight.

DO NOT shake the autoinjector pen.

  1. Check that the autoinjector pen is intact, untampered with and the orange cap securely attached, has come from a box with the name erenumab/ Aimovig on the label, and is within the expiry date. The liquid should be clear and colourless to light yellow. Discard if the liquid is cloudy, discoloured, frozen or contains visible particles. Air bubbles are normal and the autoinjector pen is still safe for use.
  2. Collect the equipment you will need to administer the treatment: Aimovig autoinjector pen, alcohol wipe, cotton wool ball and the dedicated bin provided to collect all of the waste (called a yellow sharps bin).
  3. Wash your hands thoroughly and dry them with a clean towel.
  4. Select the injection site – either the abdomen (at least two inches/ five centimetres from belly button), the front of the thigh (at least two inches/ five centimetres above the knee or two inches/ five centimetres below the groin), or the back of the upper arm. You should not inject into areas where the skin is tender, bruised, red, hardened, scarred, tattooed or has stretch marks. Choose a different injection site each time.
  5. Clean the chosen injection site with the alcohol wipe provided and leave to dry for a minimum of 10 seconds. Do not touch this area again before injecting.

To inject:

  1. Make sure the orange protective cap is on before beginning.
  2. Remove the orange protective cap from the autoinjector pen only when you are ready to inject. Once uncapped, the pen must be used and you must not attempt to recap it. It is important that you pull the cap straight off and do not attempt to twist or bend the cap off and that you immediately dispose of the cap. DO NOT attempt to reveal the needle.
  3. It is important that you do not push the grey start button at the opposite end until the point that you are about to inject.
  4. Where you have selected to inject, either create a firm skin surface by stretching the skin taut or pinch the skin to create an area about two inches/ five centimetres wide.
  5. Place the uncapped yellow end of the autoinjector pen flat against the skin selected for injection, holding the pen at right angles (90 degrees) to the skin.
  6. Press the pen firmly into the skin until the autoinjector pen cannot be advanced any further.
  7. When you are ready to inject, whilst maintaining the pressure of the pen on the skin, press down and hold the grey start button at the very top end.
  8. Hold down and listen – the first click means that the injection has started and you should keep holding down. You will hear a second click about 15 seconds later (the grey plunger should be easily visible) and you should keep holding the pen in place for another couple of seconds after this to ensure all the medication is injected.
  9. Check that you can see that the yellow plunger has moved into the treatment end viewing window and then, with care, fully remove the needle from your skin by pulling the pen straight up. Discard the used autoinjector pen unit directly into the yellow sharps bin. This is a single use autoinjector pen. Do not attempt to reuse it.
  10. Apply gentle pressure at the injection site for a few seconds using a clean, dry cotton wool ball. DO NOT rub the injection site.
  11. Always discard and dispose of used autoinjector pen units in your yellow sharps bin and never attempt to throw away any part in your household waste. You must never attempt to recycle your sharps bin; when full it should be disposed of appropriately, as advised by the supplier. The home care company who deliver your medication and sharps bin will advise you on arrangements for correct disposal.

You may find the video produced by the manufacturers of erenumab/ Aimovig a useful reminder of how to administer the autoinjector pen. This can be found at

Side effects

As with all medications, there are potential side effects, which may occur in a small number of patients. If you notice any worrying signs or symptoms (as below) please inform your general practitioner (GP) and neurologist as soon as possible.

The most common reported effects, occurring in 1- 10% of patients, are:

  • transient mild to moderate injection site pain
  • skin reactions such as redness, bruising, and swelling

Less common reported effects include injection site itching and a rash. The majority of skin reactions are apparent within one hour and will resolve over 24 hours, although these can take up to five days to resolve following the injection.

Other common reported effects, occurring in 1-10% of patients, are:

  • constipation
  • generalised itch (called pruritus)
  • muscle spasms
  • hypersensitivity reactions in keeping with more significant allergy including hives/ urticaria (pale red bumps or weals), swelling/ oedema, swelling of the lips/ tongue called angioedema and, if very severe, anaphylaxis.

Rarely, high blood pressure may emerge or high blood pressure management become insufficient during treatment with erenumab. Your blood pressure should be checked in the clinic before you start treatment and, if you continue this treatment, long-term. If you have a history of being treated for high blood pressure, you will be asked to check your blood pressure monthly as a precaution.

It is important to note that allergic reactions can occur several days to a month after using erenumab. You should remain vigilant for signs or symptoms during this time.

Seek emergency medical review immediately if you have any of the following symptoms, which may be part of an allergic reaction:

  • swelling of your face, mouth, tongue, or throat
  • difficulty breathing

For those who have latex-sensitivity, it should be noted that the removable cap of the Aimovig autoinjector pen contains dry natural rubber latex, which may cause allergic reactions in individuals sensitive to latex.

Please ensure you inform any doctor/ nurse/ pharmacist involved in your care that you are being treated with erenumab/ Aimovig.

Missed doses

If you miss or have to delay a dose, you should take the missed dose at the earliest opportunity. The next scheduled dose should be readjusted from this time point; the four weekly clock restarts from the day you took the missed dose. You must never administer a double dose to make up for a missed dose.


Routine observations including your blood pressure and pulse rate should be performed prior to first starting treatment and these will be done in the clinic by your neurology team. Your blood pressure and routine blood tests including liver function (LFTs) will be performed by the hospital prior to commencing treatment and, if you continue treatment beyond three months, again at four months. This should be organised by the hospital or your GP. If the initial blood tests performed when you first start treatment are abnormal, these will need to be repeated at three monthly intervals; regardless of whether or not they are continued will depend on the results. If the initial blood pressure is elevated, treatment will be postponed until your neurologist is satisfied that it is under control and your blood pressure will need to be monitored monthly in the first year.

In order to receive treatment, it is essential that you keep a headache diary for the three months preceding treatment. You will be expected to complete your headache diary daily and present this to your neurologist/ clinical nurse specialist at the time of review. Without an ongoing complete headache diary, you will not be considered for treatment beyond three months.

Stopping erenumab

Do not stop taking erenumab unless your doctor tells you to, as this may cause a dramatic worsening of your headache.

Pregnancy and breastfeeding

Erenumab is not recommended for management of migraine if you are pregnant, actively planning a pregnancy or breastfeeding. Women of childbearing age should take adequate contraceptive precautions for the duration of the treatment. No data is available to recommend how long after stopping erenumab it is safe to become pregnant. We therefore recommend that on stopping erenumab, you continue contraception for a further six months, as it is considered this drug may stay within the body up to this long.

This leaflet should be read in conjunction with the product characteristic leaflet that can be found inside all boxes of medication. The use of any medicine is based on considerations of how benefits outweigh potential side effects.

Your prescribing doctor will discuss the risks and benefits of the medication as it relates to you and answer any further questions you may have. Please contact the refractory headache team in the neurology department on 01223 216760 if you have any queries.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151