by Gloria Rothenberg
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.
Providing patients with these treatments is not the complete solution, the researchers explained, emphasizing the need for treatments that are tailored to patients' needs, and are administered for the necessary duration.
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.
Despite the high level of evidence supporting the use of topiramate, the treatment's side effects might harm skin, weight status, bone health, kidney function, and more.
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 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.
Fatigue was the most commonly reported side effect associated with the drug. Patients on amitriptyline were also more likely to gain weight than patients on other treatments, such as topiramate. In a trial that compared amitriptyline with topiramate, patients on amitriptyline were likely to gain weight while those on topiramate were likely to lose weight.
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 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.
"Medical providers must know the consequences of long term exposure to medications used to treat migraine," warned Starling. In regards to new treatments, "Many options are on the horizon and currently undergoing clinical trials," she added.