Howard Berkowitz wrote in message ...
In article ,
(Fred the Red Shirt) wrote:



The least toxic of these is used theraputically,

No, the most toxic is Type A, which is also the active ingredient in the
therapeutic drug Botox.

Thanks.

But: http://www.cignamedicare.com/partb/l...u/96-003-1.htm

tells us that A and B are both approved by the FDA for theraputic
use.

Here is a more comprehensive overview:

http://www.emedicine.com/pmr/topic216.htm

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FF