Preventive medication is recommended for people with migraine who get frequent or severe attacks.¹ Preventive medication is taken regularly (e.g. a daily oral tablet or a monthly injection) to try and stop attacks from coming on and dampen down the intensity or duration of attacks.
However, international research has found that preventive medication for migraine is under-used.² For example, a large US study of people with migraine calculated that 40.4% were eligible for preventive treatment but only 16.8% were currently using preventive medication.³
Preventive medications are used not only to reduce the pain and disability from frequent, severe migraine attacks but to try and avoid progression of episodic migraine (headache on 14 days or less a month) to chronic migraine (headache on 15 days or more a month) and to manage medication adaptation headache (a chronic headache that can develop in response to high use of acute medications over three months or more). So there‘s a lot at stake for people who are eligible for preventive treatment but don’t get it, for whatever reason.
We wanted to know about use of preventive medications in Aotearoa New Zealand, and whether people with migraine were receiving appropriate preventive treatment. From the 2022 Migraine in Aotearoa New Zealand (MiANZ) Survey, we determined respondents were eligible for preventive treatment if they had:
Eight or more headache days a month; and/or
Moderate to severe disability, as measured by the Migraine Disability Assessment Scale (MIDAS), that measures the impact of migraines on daily life.⁴
This was based on the data we’d collected and gave us a conservative estimate of the number of people eligible for preventive treatment. The estimate is conservative because prevention can also be appropriate for people with fewer than eight headache days a month, for example, if disability is high, if acute medications are ineffective or not well tolerated, or for specific types of migraine, including hemiplegic migraine, migraine with brainstem aura. We didn’t ask about all this in as much detail, since we had so many questions and didn’t want our respondents to get overloaded and give up, or trigger a migraine attack! So our results are likely to be an underestimate of the true number of people eligible for preventive medication.
Having said that, we found that nearly three quarters (74%, n=393) of survey respondents were eligible for preventive medication, confirming that a high proportion of respondents had frequent and disabling migraine attacks. We then looked at the number of people who were currently using any prescribed preventive medication for migraine, including antidepressants, antiepileptics, antihypertensives, sandomigran, calcitonin gene-related peptide (CGRP) monoclonal antibodies, Botoxᵀᴹ and melatonin. Half of survey respondents (n=249) were currently taking a preventive medication and the other half (n=247) were not.
When we looked at current preventive medication use by eligibility for preventives, we found for those currently taking preventives, the majority (85%) would be considered eligible for preventive treatment, according to our criteria of headache frequency and disability. Of concern, nearly two thirds (64%) of those not currently taking a preventive would be eligible for one. This indicates something amiss. A large number (n=158) of people with severe and frequent migraine attacks were not getting appropriate preventive treatment.