In October 2010, the Food and Drug Administration (FDA) approved onabotulinumtoxinA (Botox-A) injection therapy for the treatment of chronic migraine, and Botox-A remains the only treatment so approved for that specific indication. First learning of this intriguing option for headache management, patients naturally tend to have many questions regarding the use of Botox-A.
1. How many injections does each treatment involve, and what are the areas injected? The protocol for use of Botox-A injection therapy for treating chronic migraine is based upon the clinical research studies that earned the treatment its FDA approval and subsequent guidelines provided by the FDA. Each treatment involves 31 injections (5 Botox-A units per injection, for a total of 155 units). Areas injected include the bridge of the nose, the forehead, the temples, the back of the head, the neck, and the upper back (just above the shoulder blades).
2. Does it hurt? A very small, very sharp needle is used to perform the injections, and the injection process itself is not especially painful. Botox-A mixed with saline (salt water) can produce a brief burning sensation at the injection site. When treatment is performed by an experienced injector, the entire process requires no more than 10-15 minutes and is typically well tolerated. Immediately after the treatment, the vast majority of patients are able to return to their routine daily activities.
3. When can I expect improvement? Especially with the first set of injections, any improvement in your headache disorder may be delayed for as long as 10-14 days. A number of patients who fail to experience any improvement following their first Botox-A treatment may respond quite well when treatment is repeated. Even so, patients who note no improvement in their headache disorder after 2 (or perhaps 3) treatments are unlikely to become responders if treatment is continued.
4. What are the potential side effects of Botox-A injection therapy for chronic migraine? While Botox-A is a remarkably “clean” treatment for the prevention and suppression of headache, side effects can occur. The most common of these is neck pain and stiffness, often accompanied by what has become known as “wobbly neck” or “bobble head.” Injection of Botox-A into the muscles of the neck and upper shoulders may cause temporary partial weakness in those muscles, and the pain and stiffness patients experience is believed to result from those muscles (and other adjacent muscles that were not injected) working “overtime” to help keep the head upright. Regardless, the Botox-related weakness and the pain/stiffness resolve within days to weeks, and in the interim, symptomatic treatment with an anti-inflammatory drug may be quite effective for the pain. Muscle relaxants are to be avoided, as they may worsen the problem (muscle weakness) that precipitated the pain in the first place.
Less common side effects include a temporary drooping of the eyelid, and rarely, flu-like symptoms (diffuse muscle aches, fever, a general feeling of illness); the risk of the former may be reduced by your physician using optimal injection technique, and the latter is self-limited, typically lasting only a few days at most and unlikely to recur with future injection treatments. When eyelid droop does occur, the side effect reverses within weeks.
5. How often must I have injections, and how long will the treatments continue? The studies upon which the FDA based its approval of Botox-A involved a schedule wherein the participating subjects received sets of injections every 3 months, with a total of 5 treatments over 15 months. The risks associated with more frequent administration of Botox-A for chronic migraine are unknown, and the 3-month interval between injections remains the standard of care. In clinical practice, it appears that some patients receiving Botox-A will improve to the point where injection therapy may be discontinued without relapse to chronic migraine, but as yet, we lack the means to identify those patients in advance.
6. May I take other medications for headache while I’m receiving Botox injection therapy? Yes. Aggressive treatment of acute migraine headache with appropriate medications used in an appropriate fashion and at a frequency that will not cause medication overuse (“rebound”) headache will assist Botox-A in the effort to achieve a remission of your chronic migraine back to the episodic form of that headache disorder. As for oral medications intended for migraine prevention, many clinicians have found them to be complementary to Botox-A in suppressing chronic migraine, and there is no convincing evidence that use of medications intended for migraine prevention will block the positive effect of Botox-A.
7. How much does it cost? The cost of Botox-A injection therapy varies somewhat from region to region and medical practice to medical practice. In any event, the drug is relatively expensive, and the nonadjusted cost of drug plus procedure may exceed $3000. Fortunately, most insurance carriers (including Medicare and Medicaid) now “cover” the treatment, and you will be liable only for a co-pay, which will amount to a small fraction of the nonadjusted charge. Be aware that virtually all private insurers require precertification; to receive Botox-A injection therapy without precertification could result in your being held responsible for the entire charge.
8. How long will the injection procedure take, and how will I feel afterward? Again, when the treatment is performed by a skilled and experienced injector, the procedure should require no more than 10-15 minutes and can be performed in a standard examination room. Afterward, you should be able to immediately resume your routine activities. The Botox-A injections over your forehead will raise small “bumps,” but these will vanish spontaneously within hours and more quickly so if you apply ice to the region. With relative infrequency, the injection procedure may precipitate a headache that can vary in intensity from mild to severe. Conversely, do not expect Botox-A injection therapy to be effective for acutely treating any headache you may have at the time of treatment; as indicated under question number 3, and especially with the initial set of injections, the therapeutic response to Botox may be delayed for up to 2 weeks.
John F. Rothrock, MD
University of Alabama,
Birmingham, AL, USA