Botox for Migraine
In October 2010, Botox brand of botulinum toxin (OnabotulinumtoxinA) became the first medication FDA approved for treatment of chronic migraine. There were two essentially identical trials perfomed and the results were published by Dr. David Dodick here.
In a double blind placebo controlled study, patients were either treated with a standardized protocol of 155 to 195 units of Botox or placebo. The primary outcome was the change in the number of headache day per month. In the treated group, there was a decrease of 8.4 days versus a decrease of
6.6 days
in the placebo group. Importantly, the treated group also had less headache related disability.
At first glance, it appears that the benefit for Botox is relatively modest. I think the results are more impressive than they first appear. I have used Botox in my practice for over 15 years. In general, the benefit lasts for 3 to 4 months and then has to be repeated. At one time, insurance covered the procedure but in the last several years, it has been almost exclusively cash pay. My own experience with this therapy on patients is that a minority of patients have a large
benefit. Therefore, I suspect the average is relatively modest. Diseases with pain are subject to large placebo responses. This is a relatively refractory disease and no other treatment has achieved FDA approval for this indication. Despite this, I suspect insurance companies will require patients to first fail a couple of other preventives before proceeding with this therapy.
Botulinum toxin is almost side effect free. The only side effects are related to over-injection and weakening muscles more than desired. The side effects always wear off. They typically wear off before the benefit wears off. Some patients get a good initial response to botulinum toxin only to have it wear off prior to 12 weeks. For these patients, I currently am using Zytaze off label in a hope to get a longer response.
Botulinum toxin requires binding to Zinc in order to function. Dr. Soparker and associates demonstrated that the use of Zytaze (a combination of Zinc and phytase) resulted in extending the benefit of botulinum toxin (at least Botox brand for blepharospasm and forehead wrinkles).