Botox (onabotulinumtoxinA) has been approved for the prevention of chronic migraine in adults by the US Food and Drug Administration (FDA). The approval is the culmination of a decade’s worth of speculation and research, which was sparked when doctors who use the formulation to reduce facial lines noticed that some patients also experienced a reduction in headaches.
In a statement, Allergan Inc., the maker of Botox, said the approval applies to people with chronic migraine, which it defines as a “distinct and severe neurological disorder characterized by patients who have a history of migraine and suffer from headaches on 15 or more days per month with headaches lasting four hours a day or longer.”
To treat chronic migraine, qualified healthcare professionals will administer injections of the drug into seven specific head and neck sites. Results typically last three months, so injections are given approximately every 12 weeks.
“Chronic migraine is one of the most disabling forms of headache,” Russell Katz, MD, of the FDA, said in a news release. “This condition can greatly affect family, work, and social life, so it is important to have a variety of effective treatment options available.”
The most common side effects when used for chronic migraine were neck pain and headache. The most serious possible adverse events occur if Botox spreads to other areas of the body, which can cause life-threatening difficulty with swallowing and breathing. The FDA has added a boxed warning to this effect, but noted that “there has not been a confirmed serious case of spread of toxin effect when (the drug) has been used at the recommended dose to treat chronic migraine” or other conditions.
The FDA approval was based on the results of two studies involving 1,384 adults in North America and Europe. It comes on the heels of Allergan announcing it would pay $375 million in fines after pleading guilty to a charge of misbranding related to off-label use of botulinum toxin for headaches, pain, spasticity and juvenile cerebral palsy. In addition to that fine, the company agreed to pay $225 million to settle civil claims brought by the Department of Justice.