Long-term use of migraine preventive medications

There’s very little about managing migraine that’s easy.

This is especially true when our migraine attacks become so severe or frequent that they can’t be adequately controlled with acute medication and we have to consider preventive therapy. Unlike acute medication, which we take at the time of a migraine attack, preventive therapy means we’re committed to taking medication every day (or an injection every four weeks, in the case of the new calcitonin gene-related peptide (CGRP) treatments, like Emgality).

No one likes taking medication. It’s annoying and intrusive. It can be hard to remember to take a daily pill, it can make us feel like sick people when we want to feel well, and all medications can have side effects. But we do it because we hope the benefit we get from the medication is more than the harms from it.

But we have to remember there are risks from taking any medication, especially for a long time. Many of the medications used for migraine prevention not only have side effects but also have long-term risks. This may not apply to the CGRP medications, which have an excellent safety profile so far, and few significant side effects, but they will need to be used and monitored for a decade or more before we are confident they don’t have any as-yet unknown, rare or long-term adverse impacts.

For most people, the risk of taking long-term medication increases over time and older people are more likely to be affected. As we age, our kidneys and liver can start to function less efficiently, so medications are not as well processed and cleared by the body. We might be taking medications for other conditions and then we get a higher chance of drug interactions. Older people taking tricyclic antidepressants such as nortriptyline (Norpress) and amitriptyline (Amirol) may be at an increased risk of developing dementia.

At other times of life, the use of migraine preventives can present other hazards. For women who want to become or are pregnant, some preventive medications can be harmful to the developing baby, particularly anti-convulsants such as sodium valproate (Epilim). For other preventives, the effect on the pregnancy may not be known.

It’s important to remember that you don’t have to take a migraine preventive medication forever. When starting one, it’s recommended you take it for 2–3 months at the highest tolerable dose, to see whether it’s effective in reducing the frequency and severity of migraine attacks. If it’s effective, and the side effects are minimal or bearable, experts recommend continuing the treatment for 6–12 months, after which it should be reviewed with your doctor. Consider the benefits, looking at the impact on migraine days and quality of life, weigh up potential harms, such as side effects and any risks associated with the medication, and decide whether you want to carry on with it, or trial coming off it or reducing the dose.

If you come off the medication and migraine attacks increase or relapse, you can start another treatment cycle. If this happens, or if you choose to continue the medication, another review with your doctor in 6–12 months is warranted. Things can change. Sometimes the preventive medication stops being effective over time and you may need to try a different one. This practice of regular review means that we can keep assessing where we are and what we need and avoid the rut of accepting the status quo when a change may be needed.

One caveat – it’s not yet clear what is the optimal duration for taking the new injectable CGRP medications. In some countries, insurance companies mandate that people stop taking these medications after a period of time (e.g. 6 months). Many people end up back on them, because their migraine attacks recur. It may be that these have to be taken continuously in order to be effective, but we don’t know for sure yet. But the same principle of regular review and assessment applies, perhaps even more so as these medications are not yet funded in New Zealand. The financial cost is another factor to weigh up.

People with migraine manage hard things every day – managing our medication regimens is just one more.

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