Migraine prevention treatments, which can have a variety of adverse side effects, should be administered for more than 6 to 12 months to achieve the best results, an expert opinion and review of the literature suggests.
Even though the current recommendation for treatment length is 3-6 months, research has shown that more time is better: in one study 76% of patients who continued treatment for 24 months were pain-free for the next three years (without treatment), whereas only 44% of patients who continued treatment for 12 months remained pain-free. However, the side effects of certain treatments might be very severe, researchers said…
"Despite the availability of multiple evidence-based guidelines providing recommendations on migraine preventive treatment options, research suggests that approximately 40% of migraine sufferers would benefit from preventive therapies, while only 13% receive them," they explained.
"The majority of patients will need long term medications for the prevention of migraine, thus it is crucial for physicians to be aware of adverse effects due to long term exposure to the medications," said Starling in an email to MedPage Today…
Topiramate, a migraine prevention treatment with level A evidence supporting its use against headaches, was tested by researchers. They found that discontinuing treatment after six months leads to withdrawal consisting of worsening headaches, while continuing the treatment beyond six months leads to fewer and less severe headaches.
Those who experienced adverse withdrawal symptoms at the 6-month mark were put back on the drug. Discontinuation was attempted a second time after another 6 months had passed and patients again experienced worsening of headaches, suggesting that a prophylaxis period longer than 12 months is most likely necessary for these patients….
Valproate products, like topiramate have level A evidence to back their treatment for migraines.
Researchers claim that divalproex sodium (one valproate product) was effective as a long-term treatment option, but that side effects were likely to occur early on, and [headaches?]were likely to worsen if patients discontinued treatment prior to completing its optimal duration…
Amitriptyline, an antidepressant medication, only has level B support for migraine prevention. In a study, patients' likelihood of going into remission increased if they had been taking the treatment for a longer period of time…
Like amitriptyline, venlafaxine is an antidepressant and also received level B support for the purposes of the current review. However, its adverse effects have only been observed for the treatment of anxiety and depression, and not for the prevention of migraines.
Propranolol is a beta-blocker with level A evidence in support of its treatment in preventing migraines. In one trial, researchers found that patients discontinued taking the medication early on due to the onset of harmful side effects. These included but were not limited to dizziness, diarrhea, and insomnia.
This treatment [OnabotulinumtoxinA] is "the only FDA-approved treatment for chronic migraine based on the PREEMPT trials," said the authors who also explained that this treatment is given through series' of injections.
This was the only treatment out of the ones analyzed that did not seem to cause worse migraines when termination occurred within the first 6 to 12 months, according to the article.
VanderPluym J, Evans RW, Starling AJ. Long-Term Use and Safety of Migraine
Preventive Medications. Headache. 2016 Aug 1. doi: 10.1111/head.12891. [Epub
ahead of print] PubMed PMID: 27477594.
Migraine preventive medications are used to reduce the frequency, severity, and disability of migraine attacks. Once migraine preventive therapy is initiated, the question of how long to maintain this therapy arises. This article will explore the literature pertaining to the long-term use of migraine preventive medications, including length of treatment and safety with long-term exposure.