The safety and efficacy of onabotulinumtoxinA for CM was demonstrated in the pivotal phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) trial. In this trial, patients were treated every 12 weeks whether or not their headaches had returned to baseline levels and the primary outcome period was after two treatment cycles. At baseline, these patients had more than 19 headache days, and after two treatment cycles, their headaches had been reduced by 8 to 9 days per 28 days. The responder rate analysis of the study population shows that about 25% of patients improved by 75% in terms of a reduction of migraine days. In my practice, I usually do three cycles 12 weeks apart, and only if there is no change in headache frequency after this, do I change treatments. In the pivotal trials, the first statistical separation from placebo occurred in the first 4 weeks. There is a small subgroup of patients who fail to respond to the first two treatments and only start to respond after the third treatment.4-10

The recommended dose is 50 Units per axilla. The hyperhidrotic area to be injected should be defined using standard staining techniques, e.g., Minor's Iodine-Starch Test. The recommended dilution is 100 Units/4 mL with 0.9% preservative -free sterile saline (see Table 1). Using a sterile 30 gauge needle, 50 Units of BOTOX (2 mL) is injected intradermally in 0.1 to 0.2 mL aliquots to each axilla evenly distributed in multiple sites (10-15) approximately 1-2 cm apart.

Serious and/or immediate hypersensitivity reactions have been reported. These reactions include anaphylaxis, serum sickness, urticaria, soft-tissue edema, and dyspnea. If such a reaction occurs, further injection of BOTOX® should be discontinued and appropriate medical therapy immediately instituted. One fatal case of anaphylaxis has been reported in which lidocaine was used as the diluent, and consequently the causal agent cannot be reliably determined.

Still, Botox's use for depression raises a question that confounds some researchers. In some cases, how Botox works is evident: the toxin can block the signals between nerves and muscles, which is why it can help calm an overactive bladder, say, or a twitching eye, or the facial muscles that make wrinkles more apparent. In other cases, however (with migraines as well as with depression), scientists are flummoxed. They may have noticed that the drug works for a given condition, but they aren't always sure why--in sciencespeak, they don't know what the mechanism is.

In 2005, the national average cost of a BOTOX® injection was just over $375. However, the cost of BOTOX® treatment varies from area to area. In 2005, the northeastern United States had the highest BOTOX® average cost, at just over $500, while the western states had the lowest average, at under $370. It is important to keep in mind that these statistics may be somewhat misleading, as the cost of BOTOX® injections in Los Angeles will almost certainly be higher than BOTOX® treatment price in say, a rural area of Pennsylvania.

Botox is injected in and around the head on an average of every three months. It blocks signals from nerves and paralyzes the muscles, ultimately preventing migraines. It is known to relax the muscles that usually contract during migraines. It’s also the only FDA-approved medication to prevent migraines before they even start! It’s known to prevent about nine migraines per month.

Do not receive BOTOX® Cosmetic if you: are allergic to any of the ingredients in BOTOX® Cosmetic (see Medication Guide for ingredients); had an allergic reaction to any other botulinum toxin product such as Myobloc® (rimabotulinumtoxinB), Dysport® (abobotulinumtoxinA), or Xeomin® (incobotulinumtoxinA); have a skin infection at the planned injection site.