Botox Approved for the Treatment of Chronic Migraines
The US Food and Drug Administration has approved injections of onabotulinumtoxinA, commonly known as Botox, for the prevention and treatment of chronic migraine headaches in adults. The wrinkle-fighting formula by Allergan was also approved in March for muscle spasms and is being studied for the treatment of other conditions, such as Parkinson’s, cerebral palsy, and overactive bladder.
Migraines, defined as a debilitating headache with intense pulsing or throbbing pain often accompanied by nausea and sensitivity to light and sound, affect about 12% of Americans. Patients with chronic migraine headaches experience them more than 14 days a month, lasting four hours or longer. It is three times more common in women than men.
The FDA approved Botox after studies found the injections to be effective in two studies involving 1,384 adults in North American and Europe. Patients who received Botox reported slightly fewer “headache days” compared to patients given a placebo.
The injections are given at intervals of about 12 weeks into seven specific sites around the head and neck to dull future headache symptoms. Results are expected to last up to three months, depending upon the individual patient.
The drug is not approved for patients who have episodic migraines, or those occurring fewer than 14 days a month.
Patients should ask their doctors whether Botox is appropriate for them. The most common adverse reactions are neck pain and headache, says the FDA. There is also a risk of the botulinum toxin spreading to areas outside the injection site, causing symptoms similar to botulism, although the agency is unaware of any confirmed cases of this.