Re: question re comt inhibitors

[Brian Collins <bjc@xxxxxxxxxxxxxxx>]

On Sat 23 Oct, janet paterson wrote:
> hi all
>
> after reviewing the pmid abstracts on comt inhibitors
> i started mulling
>
> i hadn't realized
> that tolcapone crosses the blood brain barrier
> while entacapone doesn't
>
> if the work that this class of med does
> [saving lovely levodopa from arterial ambush by those vile venous comt 
> conspirators]
> is done in the bloodstream prior to arrival at the brain station
> why would either of them have to cross the blood brain barrier?
> anyway?
>
> just a late nite thote about cone pone


I wish someone coould make an authoritative statement on the ability of
Tolcapone and/or Entacapone to cross the blood/brain barrier. Janet has heard
that Tolcapone does, and Entacapone doesn't, while I am quite clear that I
was told some time ago (When Tolcapone was originally approved) that
Tolcapone cannot cross the barrier. I remember it well, because I asked my
friendly local neurologist how Tolcapone worked, and he confessed with
some embarrassment that he didn't know, because of the above inability to
cross into the brain. It may also be relevant that Tolcapone was withdrawn
because it caused liver failure (in a  small number of people). i.e. in
the body, not the brain.

--
Brian Collins  <bjc@xxxxxxxxxxxxxxx>