In exciting headache news, Botox brand of botulinum toxin A was FDA approved October 15, 2010 for chronic daily headache. To have chronic daily headaches, you have to have a headache more than 50% of the days in each of the last 3 months. To have chronic migraine headache, at least 8 of these headaches each month have to meet the criteria for migraine headache. This is the first medication approved for chronic daily headache. The study that proved its effectiveness can be found here.
Botox was tested in two studies that were identically designed. Briefly, patients who met criteria for chronic daily headache with a history of migraine were randomized to either receive Botox (155 to 195 units) or placebo. In the end, the treated group had 8.4 fewer headache days compared to 6.6 fewer headache days for the placebo group. While the difference between the two groups is relatively small, this represents the first medication to approved for this indication. Chronic daily headache is a relatively refractory form of migraine headache and the placebo response for pain studies is quite high. Therefore, it is difficult for treatments to be proven effective in this disease. Allergan deserves a lot of credit for pursuing this indication instead of the easier indication of frequent migraine headache.
Valproic acid, Topiramate, and long acting Propranolol are FDA approved to prevent frequent migraines with headaches that are less than 15 days per month. These medications, as well as others, are used off-label for chronic daily headache and chronic migraine as well. My website includes additional information on migraine, chronic daily headache as well as prevention of frequent migraine.
I have used Botox for migraine headache for more than 15 years. Prior to this approval, insurance companies rarely paid for this therapy. I suspect all insurances will cover this treatment after a couple of trials of less expensive treatments. I think it will be essential to keep an excellent headache diary for 4 weeks before and after the botulinum toxin treatment in order to determine how effective this treatment is for an individual patient. Besides headache days, keeping track of disability hours each day I think is the best indication for effectiveness of treatment. The electronic headache diary app iHeadache includes all of this information and can prepare reports for you and your physician to assess how well Botox (or any other preventive treatment) works for you.