Botox injections have been used in prevention of migraines but new research shows that its effect is only modest. Among chronic sufferers who had at least 15 migraines a month, the treatment prevented, on average, about two headaches a month. Botox was no more effective than some of the most widely prescribed drugs used for migraines when the treatments were compared.
Botox or botulinum toxin type A injections are known for their cosmetic application to remove facial wrinkles. It was approved to prevent migraines in 2010, but only for patients who experience 15 or more migraine headaches a month. Today, about half of the $1.6 billion annual sales of Botox are from migraine and other non-cosmetic uses.
Researchers from the Medical College of Wisconsin, Milwaukee, reviewed previous studies on botulinum toxin A when used for the treatment of migraine, tension or chronic daily headaches in adults. In the new study, in the Journal of the American Medical Association, researchers analysed findings from 27 trials with nearly 5000 participants that compared Botox to placebo and four studies that compared it to other migraine treatments.
The analysis found that Botox injections were not effective for preventing migraines in patients who have less than 15 headaches a month. The treatment also did not appear to benefit patients with chronic tension headaches. But Botox-treated patients with chronic migraines and daily headaches had an average of two fewer headaches per month.
Researcher Jeffrey L. Jackson, of the Medical College of Wisconsin, said it is clear that much better migraine therapies are needed, especially for the most frequent sufferers. “All of the available migraine treatments benefit some patients and not others,” he told WebMD. “Until we really understand migraines it will be hard to design treatments that work well for all patients.” He added that while the average Botox patient may not experience big improvements, results for some patients might be dramatic.
According to the study authors, “Our analyses suggest that botulinum toxin A may be associated with improvement in the frequency of chronic migraine and chronic daily headaches, but not with improvement in the frequency of episodic migraine, chronic tension-type headaches, or episodic tension-type headaches. However, the association of botulinum toxin A with clinical benefit was small.”
Headache specialist Satnam Nijjar, of Johns Hopkins University School of Medicine, said the research analysis will surprise few clinicians working in the field. “This review emphasizes that most patients experience modest benefits, but we already knew that,” he told WebMD. He says most of his Botox patients have tried several drugs to prevent migraines and lessen their severity, and they either did not benefit or could not take the side effects.
Anti-seizure drugs, such as topiramate and gabapentin, are widely prescribed for migraine prevention, but these drugs can have side effects such as fatigue,dizziness, and nausea. But he said patients who don't like needles may find drugs preferable to Botox, which involves 25 to 30 small injections in the head region every three months or so.
The AAN's latest recommendations found that numerous drugs, such as the seizure drugs divalproex sodium, sodium valproate and topiramate, along with the beta-blockers metoprolol, propranolol and timolol, are effective for migraine prevention. The guidelines also noted herbal drugs such as petasites relieved migraine pain and nonsterodial anti-inflammatory drugs, such as ibuprofen and naproxen sodium should be offered to people with migraines to reduce the frequency and severity of attacks. Botulinum toxin A, otherwise known as Botox, was not mentioned in the recommendations.
Headache researcher Dr. Vincent Martin, from the University of Cincinnati, said doctors have known for years that Botox doesn't help people will less-frequent headaches - and the new review “gives a more definitive conclusion” on that. “I would argue it's a very important treatment for many people with chronic migraine - not for everyone,” he told Reuters Health.
Martin agreed that doctors often take into account more than just headache frequency when they prescribe the injections. “Just looking at headache days per month may not tell the whole story,” he said.
A spokesperson for Botox manufacturer Allergan Inc. said the study reinforces its role as a treatment to prevent chronic migraines. Crystal Muilenburg, Allergan's director of corporate communications, says some patients in company-sponsored trials experienced a 50% reduction or more in headache days per month after two cycles of Botox, and more than 2 out of 3 patients showed some improvement.
Dr. Mitchell Brin, Allergan's Chief Scientific Officer for Botox, pointed out that previous studies have suggested people with chronic migraines who are prescribed the drug also tend to have shorter-lasting migraines on the days when they still have headaches. The difference equaled about 40 fewer hours per month with pain compared to patients given placebo injections, he said. That's “quite meaningful,” Brin told Reuters Health. “The impact on their lives is quite significant.”
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