Migraine sufferers who haven't found relief in prescription or over-the-counter medications can now seek help from the same drug that erases crows' feet and forehead wrinkles. The U.S. Food and Drug Administration last week approved the use of Botox, delivered through a couple of dozen needle pricks around the head and neck, to prevent chronic migraines—which for approval purposes means severe headaches of four hours or more at least 15 days a month. Great Britain approved Botox for the same purpose in July.
But getting needled is neither risk-free nor the solution for every migraine sufferer.
The FDA based its decision on two 24-week trials involving a total of 1,384 adults in North America and Europe. Both trials were funded by drug maker Allergan, which last month agreed to pay $600 million for illegally promoting Botox for headaches, which, at the time, were not an FDA approved use. By the end of the first trial, those who received Botox experienced 7.8 fewer migraine days during the 24 weeks than they experienced during the 24 weeks leading up to the trial compared with 6.4 fewer days for those injected with a placebo of plain salt water. The Botox group in the second trial had 9.2 fewer migraine days while the placebo group had 6.9 fewer days. Allergan published its results last March in the journal Cephalalgia, the medical term for headache. The differences are significant by clinical trial standards, but "not huge," says Avi Ashkenazi, a Doylestown, Pa., neurologist who has published papers on the subject, including one in Current Neurology and Neuroscience Reports.
Botox shots should not be the initial treatment choice even for the worst migraines, says Seymour Diamond, executive chairman of the National Headache Foundation, a source of information and advocacy for headache sufferers, and director of the Diamond Headache Clinic in Chicago, which has performed Allergan-sponsored research. "We should attempt simpler therapies," he says, such as prescribing a tricyclic antidepressant or beta blocker, before resorting to Botox. But he calls it a "valuable resource" for chronic migraine patients—especially those who weather headaches that cause pain on one side of the head and who haven't found relief with prescription medicines like the antiseizure drug Topamax, often given to prevent migraines.
Yet even for the likeliest candidates, Botox treatment doesn't guarantee fewer hours of throbbing or less nausea, vomiting, and sensitivity to light, the classic chronic migraine symptoms. At Diamond's clinic—which he says serves the "worst of the worst" in the migraine world—physicians have treated 600 to 800 patients over the past five years with Botox. (Physicians can legally use an approved drug "off label" to treat a condition other than the one for which it was approved.) Diamond estimates that about 30 to 35 percent of them have found meaningful relief.
Research dating back roughly 20 years has explored whether Botox could relieve headache pain, says Ashkenazi, who has been an investigator in Allergan-sponsored trials. Only recently have chronic migraine sufferers been identified as most likely to benefit. For those who do find relief, researchers believe it's because the botulinum toxin, a protein that is produced by the same bacteria that causes botulism, blocks chemicals from sending pain signals through nerve cells to the brain.
Consulting with a specialist is a must before embarking on Botox therapy, says Diamond, which means a neurologist or headache specialist familiar with chronic migraines who knows the intensity of your migraines and the remedies you have tried. "You shouldn't go to Dr. Joe Blow, who hasn't really intensely treated headache patients in his career, and ask to get Botox," says Diamond. As many as 31 injections are delivered to seven areas of the head and neck, so some risk is inevitable. About 1 percent of Botox users in the two clinical trials had to be hospitalized because their migraines became unbearable; that happened with .3 percent of those on the placebo. Between 2 to 9 percent of patients receiving Botox injections in the trials reported problems such as neck pain, muscular weakness or stiffness, bronchitis, high blood pressure, muscle spasms, and drooping eyelids.