In October 2010, the U.S. Food and Drug Administration (FDA) approved the use of Allergan’s anti-wrinkle drug Botox-A—properly known as onabotulinumtoxin-A—for the prevention of chronic migraine. As opposed to the more familiar episodic form, chronic migraine implies that the afflicted individual has experienced at least 15 days of headache per month for at least three consecutive months. That makes Botox-A the only FDA-approved treatment for a condition that affects as many as 6 million Americans and is the most common reason for referral to a specialized headache clinic, says neurologist John F. Rothrock, M.D., director of the UAB Headache Treatment and Research Program.
In studies conducted while he was on the faculty at the University of South Alabama and now at UAB, Rothrock helped to demonstrate the safety and efficacy of Botox-A as a preventive therapy for chronic migraine. This effort complements his work performed more than two decades ago, when he assisted in the development of self-administered injectable sumatriptan (marketed commercially as Imitrex, Sumavel, or their generic equivalent). Injectable sumatriptan is a safe and highly effective therapy for acute, severe migraine headache, Rothrock says, and its introduction has empowered millions of individuals with migraine to terminate migraine attacks that otherwise would have required a visit to an emergency room (ER) or simply “suffering in silence” at home.
Taking the Sting Out of Migraine
Botox-A for Migraine
• Treatment requires 31 injections involving the face, head, neck, and shoulders.
• The procedure can be performed in as little as five minutes.
• Duration of headache relief varies but lasts an average of three months.
• Studies at UAB and elsewhere show positive response in 40 percent or more of patients.
• Now that Botox-A has FDA approval for treating chronic migraine, insurance companies are more likely to cover treatment costs.
Why does a medication derived from bacterial poison (that’s what Botox is, essentially) help with headache? When it is used for cosmetic purposes, Botox relaxes facial muscles and smooths wrinkles. For migraine sufferers, it appears to have a dampening effect on their genetically hypersensitive central nervous systems. Rather than reducing headache by relaxing muscles, Rothrock says, “Botox-A appears to directly inhibit the pathway that produces the clinical symptoms which, taken altogether, are referred to as ‘migraine.’”
Rothrock and other neurologists at the UAB Headache Clinic administer Botox by injecting the drug at 31 muscle sites in the forehead, temples, back of the head, neck, and shoulders. Trained physicians can complete the entire procedure in five minutes or less, Rothrock notes.
In studies at South Alabama and UAB, slightly more than 40 percent of patients receiving Botox treatment reported that their headache frequency declined by at least half over a six-month period. Rothrock and his colleagues are analyzing the data from those studies in an attempt to identify which types of patients may be more or less likely to respond to therapy.
Consistency, Side Effects, and Cost Considerations
Most patients with chronic migraine destined to respond to Botox-A will begin do so after the initial treatment, but it can take up to two weeks before patients notice improvement, Rothrock says. Injections initially are repeated at three-month intervals, he explains, and many responders find that each successive treatment leads to an ever-greater reduction in headache frequency and severity. “Although there is some relatively mild discomfort associated with the injections,” Rothrock adds, “the payoff in headache relief generally far outweighs that discomfort for the vast majority of treatment responders.”
Before Botox-A received FDA approval for the treatment of chronic migraine, insurance companies were reluctant to pay for such treatment, Rothrock says, but that is changing—perhaps to the benefit of insurers as well as patients, he notes. In a recent study, Rothrock and his colleagues found that treating chronic migraine with Botox-A resulted in decreased ER utilization for acute headache treatment, with the associated reduction in direct medical costs exceeding the cost of Botox-A administration.
Side effects from Botox-A are rare, Rothrock points out; the most common is neck pain/stiffness, often in association with transient neck muscle weakness. Patients occasionally experience drooping of the eyelid after receiving Botox-A, but this typically resolves within several weeks, and rarely does this or any other of the treatment-associated side effects pose enough of a problem for patients to discontinue treatment.
One side effect is often welcome: Botox injections for migraine also tend to reduce forehead wrinkles.
—Written by Matt Windsor