GPs encouraged to become familiar with CGRP medications for migraine

Calcitonin gene-related peptide (CGRP) medications. They’re without doubt this century’s revolution in migraine treatment. Including both injectable monoclonal antibodies (e.g. Emgality) and oral tablets (gepants), they’re the first pharmaceuticals specifically developed for migraine, based on scientific research on how migraine attacks originate in the brain.

They target CGRP, a neuropeptide involved in the cascade of pain signals that causes a migraine attack and act to prevent attacks from occurring.

They’ve transformed the practice of headache medicine. Because they’re migraine-specific, they don’t have the side effects of other migraine preventive medications, which were developed for other conditions such as heart disease or hypertension (e.g. beta blockers and candesartan), epilepsy (e.g. Topamax) and movement disorders (e.g. Botox).

They can be very effective, at least in those whose migraine attacks are driven by high levels of CGRP (estimated to be 75-80% of people with migraine). They work well even in people who haven’t had success with other preventives. For some people, CGRP medications can start working within a few days, unlike other preventives which can take eight weeks for an effect to be felt. They work for both chronic (headache on 15 days or more a month) and episodic (headache on 14 days or less a month) migraine.

In New Zealand, we estimate 640,000 people have migraine and 45,000 people have chronic migraine. Every GP in the country will see people with migraine in their practice and many will see people with severe and disabling migraine. None of the CGRP medications are funded in New Zealand (and the gepants aren’t even available here) but chances are, they will be in the future. Even now, some people are willing and able to pay for the chance to try a medication that may help when little else has.

GPs need to support this. The CGRP monoclonal antibodies are very safe, with few side effects beyond injection-site reactions and they don’t interact with other medications. Currently, because the CGRP medications aren’t funded by Pharmac, there’s no restriction on who can prescribe them. GPs can prescribe them without referral to a neurologist. Only Emgality and Aimovig are currently available but Emgality is by far the cheaper and more available option, which means there is really only one new medication GPs have to learn about.

Some GPs may be cautious about initiating a new treatment without specialist instruction. But innovations and change are the norm in medicine. GPs routinely have to study up on new treatments, even new diseases. Migraine is a common neurological condition and most people with migraine should be managed in primary care. This is even more relevant in New Zealand, where access to neurologists, particularly headache specialists, is very limited and may be impossible in the public health system. Even in private, an appointment with a neurologist can be a long waiting game.

If you have migraine disease and are wanting to try Emgality, but your GP is reluctant to prescribe it, you can start by giving them information and resources that will answer their questions. This can include the NZ Datasheet on Emgality or the prescriber information provided by the drug company. A number of research articles, freely available online, are listed at the of this blog. You could try ‘social pressure’ by telling them that other people in the migraine community in New Zealand have had Emgality prescribed by their GPs.

If they’re still reluctant, find out what their concerns are and ask them to discuss these with a colleague with more experience. They may have legitimate questions which you need to know about also, to assess whether this is the right treatment for you. Some GPs may want a neurologist to start the prescription, which they will continue. You may be willing to go through this process but remember that at present there is no requirement for a neurologist to start Emgality. It comes down to the judgment of the GP.

If your GP is not comfortable with prescribing Emgality or is not willing to learn about new migraine treatments, there is the final option of choosing a GP with more knowledge and expertise in migraine management. You deserve care from a doctor who understands what migraine is, how it’s impacting you, and who actively works with you on making it better, which includes looking at new and different treatments. It’s not easy to find another GP and start over with building that relationship, but in the end, it may be what’s needed. You are worth it.

  1. Vincent T. Martin, Alexander Feoktistov & Glen D. Solomon (2021) A rational approach to migraine diagnosis and management in primary care, Annals of Medicine, 53:1, 1969-1980, DOI: 10.1080/07853890.2021.1995626 (available free online at
  2. Nissan GR, Kim R, Cohen JM, Seminerio MJ, Krasenbaum LJ, Carr K, Martin V. Reducing the Burden of Migraine: Safety and Efficacy of CGRP Pathway-Targeted Preventive Treatments. J Clin Med. 2022 Jul 27;11(15):4359. doi: 10.3390/jcm11154359 (available free online at )
  3. Kubota GT. It is time anti-CGRP monoclonal antibodies be considered first-line prophylaxis for migraine. Arq Neuropsiquiatr. 2022 May;80(5 Suppl 1):218-226. doi: 10.1590/0004-282X-ANP-2022-S112 (available free online at