nos-trum. pronunciation: \nos'-trum\. noun. Etymology: Latin, neuter of noster our, ours.
1. a medicine of secret composition recommended by its preparer but usually without scientific proof of its effectiveness.
2. a usually questionable remedy or scheme.
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Tuesday, August 3, 2010

Botox For Chronic Migraine? FDA Hints...Maybe

The manufacturer is completing Phase III trials.  The FDA will hold a hearing in about 3 months.  It's already been approved in the UK.

For chronic migraine sufferers any day without a headache is a good day.  Why?  Because qualifying for the diagnosis of "chronic" migraine requires 15 or more headache days a month.

So it's important to realize that we're talking about a subset of the worst migraine sufferers only.  If approved, Botox will only be for that group, because that's the group that was studied.

At this point, I'm at a loss to give a biologically plausible mechanism that could account for how this works.  I'm sure folks have a theoretical mechanism, but it strikes me that Botox operates locally and migraines are commonly due to a diffuse vascular spasm.

Maybe looking at some of the Phase trial data would help.  For the original studies try here, here, and here.

For Onion Peelers,
A total of 1384 adults were randomized to onabotulinumtoxinA (n = 688) or placebo (n = 696). Pooled analyses demonstrated a large mean decrease from baseline in frequency of headache days, with statistically significant between-group differences favoring onabotulinumtoxinA over placebo at week 24 (-8.4 vs -6.6; P < .001) and at all other time points. Significant differences favoring onabotulinumtoxinA were also observed for all secondary efficacy variables at all time points, with the exception of frequency of acute headache pain medication intakes.

Note that there was a strong placebo effect.  Even with placebo there was a decrease of 6.6 headache days per month, compared to the treatment group which had a decrease of 8.4 days.  I'll bet that even if the results weren't statistically significant, for 6 less days of headache alone, they would greatly desire any form of subcutaneous injection, placebo or otherwise.

One other caution:  I can't tell if the placebo control group could ascertain whether they were getting the placebo or not.  For example, whether Botox causes a stinging sensation when injected versus a sterile saline injection.  That would bias the results.  As I say, I just don't know.

But it is worth noting that the difference between placebo and Botox was 1.8 days of headache.  Not earth-shattering.

Unless you have chronic migraine.

Doc D

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