For reasons often not obvious or perhaps not even identifiable, a patient’s migraine prevention therapy that has proven to be beneficial in keeping the migraine burden low for many months or even years rather abruptly can lose its effectiveness.

While this unhappy phenomenon rarely was observed in long-term clinical trials involving onabotulinumtoxin A (BotoxA) administered for suppression of chronic migraine and seldom has been experienced by patients treated in the author’s clinical practice, the potential for this particular type of “Botox failure” does exist. Again, this is entirely different from an absolute failure to respond to BotoxA; more than a third of chronic migraine patients will report no improvement in their headache burden consequent to treatment with BotoxA. These are instead chronic migraine patients who have been doing quite well on BotoxA therapy for a year or more and then – for no obvious reason – experience relapse to chronic migraine despite continued treatment. Why might this be?

A goodly number of patients simultaneously receive Botox from different providers for different purposes, and in the population treated with BotoxA for suppression of chronic migraine by far the most common other purpose involves cosmetic therapy. Often the treatments are scheduled weeks apart from one another, and this can pose a problem.

The body’s immune system is always on the alert for the intrusion of foreign proteins (“antigens”), and some medications are composed of proteins. If a “protein medication” is detected, the system may respond by producing “neutralizing antibodies” that inactivate the perceived invader. The Botox protein rarely evokes this neutralizing antibody response, but when it does this may affect the biological activity of the neurotoxin and negatively impact clinical response.

There is evidence to suggest that receiving multiple treatments with Botox on a schedule that permits only weeks – rather than months -  to pass between treatments may increase the likelihood of a patient developing neutralizing antibodies that potentially may reduce or eliminate its therapeutic effect. If you simultaneously receive BotoxA from different providers for different clinical indications, care should be taken to consider the timing of treatments. 

If you are receiving Botox both for cosmetic purposes and for suppression of chronic migraine, work with your providers to ensure that the two treatments are performed within no more than a few days of one another rather than weeks apart. While as much as 360 units of BotoxA may be administered safely within a given 12 week period, administering 155 units for chronic migraine and then after a period of a few weeks administering 40 units for cosmetic purposes may increase the chance of your developing neutralizing antibodies.

As in much of life, timing is everything.

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