FAQ: How is Onabotulinum A (Botox) used for migraine?

What to know before considering this preventive treatment

Migraine management involves preventive and acute treatments. Acute treatments help manage current symptoms, and preventives work to reduce the chance an attack even happens. When developing a treatment plan with your physician, Onabotulinum A may be an option. But what is Onabotulinum A and why is it used for migraine?

To learn more about Onabotulinum A, we posed some frequently asked questions to Dr. Carrie Dougherty, an assistant professor of neurology at the MedStar Georgetown Headache Center, who helped explain how this preventive treatment works and who is a possible candidate for treatment.

What is Onabotulinum A?

OnabotulinumtoxinA, also known as Botox, is a form of botulinum toxin, which is a neurotoxin. When purified and used in small doses, Onabotulinum A temporarily inhibits muscle contractions in the muscle in which it is injected and overall affects pain for approximately 3 months.

How does Onabotulinum A help migraine?

Onabotulinum A is a preventive treatment for those with chronic migraine, which is defined by 15 or more headache days per month. “Botox injections for migraine can help to reduce frequency and severity by blocking the transfer of information from the motor nerve to the muscle,” says Dougherty. “Once the procedure starts to take effect—usually within a couple of days—the Botox can decrease pain signaling in migraine.”  Because migraine attacks come with unpredictable frequency and are dependent on many factors, it may take much longer to tell if the Onabotulinum A is really working for you. In clinical trials, Onabotulinum A has been shown to reduce the number of headache days per month on average by about 50%, but it may take several treatments to tell if Onabotulinum A is working for you.

What is Onabotulinum A treatment like?

A round of Onabotulinum A treatment involves injecting a small amount of the medication into 31 specific points in the forehead, temples, back of the head and top of the neck using a small needle. “These are all points where nerves are active during migraine,” says Dougherty. “The procedure itself goes quickly, about 20 minutes. “It usually takes me longer to explain the procedure than to actually perform it.” Patients typically receive a round of injections every 12 weeks or at intervals recommended by their doctor.

Who should get Onabotulinum A for migraine?

Onabotulinum A is FDA approved for the treatment of chronic migraine, although most insurance companies require that patients fail to respond to or experience side effects to at least 2 or 3 other medications used as preventives. Once a patient has tried other oral preventives but not experienced a therapeutic response or had severe side effects, they can move on to trying Onabotulinum A, which is an interventional headache procedure. “In general, chronic patients who try two or three oral preventives and don’t have consistent results should discuss Botox as a treatment option with their doctor,” Dougherty says.

Learn more about interventional headache procedures here.

This treatment does not interact with any other medications, so it works well within a treatment plan and for those with other health issues. “Botox wouldn’t be appropriate for someone with a history of neuromuscular disorders or pre-existing conditions such as difficulty breathing and myasthenia gravis,” says Dougherty. It is also not appropriate for patients who are pregnant or trying to become pregnant.

What are the side effects of Onabotulinum A for migraine?

Dougherty says patients sometimes report neck pain in the week following the procedure. This is due to other muscles compensating for the muscles injected with the medicine. Other side effects may include a headache the day of or day after the procedure. “Patients often see improvement by the second or third round of Botox injections,” says Dougherty. “The initial results may be a reduction in severity, noticing that an abortive medication works better or missing fewer days of work.” Onabotulinum A injected into the forehead may also temporarily change cosmetic appearance (such as wrinkle reduction and change in the arch of the eyebrow) and in severe cases lead to a reversible drooping of the eyelid.

Learn more about Onabotulinum A as a treatment for chronic migraine here. To find a headache specialist in your area who can diagnose you and create an effective treatment plan, use our Find a Doctor tool.