Migraine: a complex neurological condition
Migraine is far more than "just a headache". Those affected often suffer from recurrent, moderate to severe headache attacks, frequently accompanied by nausea, sensitivity to light and sound, and visual disturbances. According to estimates, around 10 to 15 per cent of the population in Austria are affected by migraine – women considerably more often than men.
While mild or infrequent forms of migraine can often be managed well with acute medication, people with frequent or particularly debilitating attacks may need so-called prophylaxis – a preventive treatment aimed at reducing the frequency and severity of attacks. Significant progress has been made in this area in recent years: CGRP antibodies are considered an important addition to the classic migraine prophylaxis within newly reconsidered treatment strategies.
What are CGRP antibodies?
CGRP stands for calcitonin gene-related peptide, a messenger substance produced by the body that plays a central role in the development of migraine attacks. During an attack, CGRP is released in increased amounts in the trigeminal nerve. There it contributes to the dilation of blood vessels and the transmission of pain signals – and is therefore regarded as one of the key substances in the development of migraine.
Monoclonal antibodies of a migraine-specific type target this very point. They are protein molecules produced using biotechnology that specifically either:
- bind to the CGRP molecule itself and render it ineffective, or
- block the CGRP receptor to which the messenger normally attaches.
This interrupts the signalling chain that leads to a migraine attack at a decisive point.
Which active substances are available?
Several CGRP antibodies are currently approved in Austria for migraine prophylaxis. These include the active substances:
- Erenumab (targets the CGRP receptor)
- Fremanezumab (targets the CGRP molecule)
- Galcanezumab (targets the CGRP molecule)
- Eptinezumab (targets the CGRP molecule, administered intravenously)
Most of these substances are injected subcutaneously – i.e. under the skin – once a month, in some cases quarterly. After appropriate training, many patients can carry out the injection themselves at home.
How do CGRP antibodies work in the body?
Unlike classic painkillers or many older migraine preventives, CGRP antibodies intervene in the migraine mechanism in a very targeted way. Their mode of action can be described in simplified terms as follows:
1. After injection, the antibody enters the bloodstream.
2. There it binds either to the CGRP molecule or to its receptor.
3. The transmission of pain signals in the trigeminal system is dampened.
4. This can help migraine attacks to occur less frequently or to be milder.
Studies show that in some of those treated, the number of migraine days per month decreases noticeably. Individual responses vary, however – some benefit considerably, others less or not at all. As a rule, after about three months it is reviewed whether a sufficient improvement has been achieved.
Who may be eligible for CGRP antibodies?
Not every person with migraine is automatically a candidate for this therapy. Austrian and European guidelines, as well as the reimbursement criteria of the health insurance providers, require certain conditions to be met.
Typical areas of use
CGRP antibodies may be considered for:
- Episodic migraine with at least four migraine days per month
- Chronic migraine with 15 or more headache days per month, of which at least eight are migraine days
- Patients in whom several classic prophylactic medications (e.g. certain beta blockers, antiepileptics or antidepressants) have not worked sufficiently, were not tolerated or are unsuitable for medical reasons
When is caution required?
As with any therapy, there are also situations in which CGRP antibodies should not be used, or only after careful consideration – for example during pregnancy and breastfeeding, in certain severe cardiovascular conditions or in cases of known hypersensitivity to the active substances. The decision should always be made individually and in consultation with a doctor.
Possible side effects
Overall, CGRP antibodies are considered well tolerated. Nevertheless, as with all medicines, side effects can occur. The more commonly reported include:
- Reactions at the injection site (redness, itching, mild pain)
- Constipation (particularly with certain active substances)
- Cold-like symptoms
- Muscle tension
Allergic reactions and changes in blood pressure have been observed less frequently. As this group of substances is still relatively new compared with established preventives, long-term data continue to be collected systematically.
How a course of treatment is organised
Therapy with CGRP antibodies is typically initiated by a specialist in neurology. The process usually includes:
- A detailed medical history and a headache diary to document migraine days
- Review of previous therapies and possible contraindications
- Application to the health insurance provider, as reimbursement is linked to certain requirements
- Training in self-injection, if administration takes place at home
- Regular follow-up checks, usually after three to six months, to assess effectiveness
If a clear reduction in migraine days is seen after about three months, the treatment is continued. If the hoped-for effect does not materialise, switching to another substance or another treatment strategy may be sensible.
CGRP antibodies as part of an overall concept
Promising as this new class of substances is, it in no way replaces comprehensive migraine care. A sustainable treatment concept still includes:
- Suitable acute medication for use in the event of an attack
- Non-medicinal measures such as relaxation techniques, endurance exercise, regular sleep and stress management
- Identifying individual trigger factors (e.g. certain foods, hormonal fluctuations, irregular meals)
- Where appropriate, psychological support, particularly in chronic cases
CGRP antibodies can therefore be a valuable building block in an individually tailored treatment plan – especially for people who have so far only benefited insufficiently from other prophylactic options.
Conclusion
The introduction of CGRP antibodies is one of the most notable developments in migraine therapy in recent years. Through their targeted mode of action, they offer an alternative for patients in whom classic prophylactic medications do not work sufficiently or are poorly tolerated. Whether and when their use is appropriate should be discussed individually as part of a neurological assessment.
This article does not replace medical advice.