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Question 23: I have read a lot lately
on nicotine patches for the treatment of T's, any thoughts or info
on that?? L.D., Australia.
Hello
L:
Here's
the scoop on the nicotine patch research --
Initial
research suggested that the benefits of a nicotine patch were to catalyze
the efficacy of classic neuroleptics (dopamine antagonists like Haloperidol).
Basically Haloperidol (a drug that blocks dopamine) seemed to work better
at eliminating symptoms if a nicotine patch was used as well.
More recent
research has better explained why this is: nicotine emulates acetylcholine,
a chemical in the brain which binds to certain cells (to nicotinic receptors)
and tells them to produce dopamine. This seems counter-intuitive: why
would something that causes MORE dopamine to be produced help to reduce
tics, when most medications used for TS work to reduce or block dopamine??
The reason is because a continuous flood of nicotine, prompting increased
dopamine production, eventually overloads these nicotinic receptors,
causing them to shut down and no longer operate. Hence while a nicotine
patch initially causes dopamine production to increase, ultimately the
result is less dopamine production.
For this
to work, the nicotinic receptors have to be constantly barraged. Therefore
smoking is NOT effective and not a solution. Even the patch is inefficient
(not to mention 70% of patients report extreme nausea from this method).
Instead now researchers are looking into drugs that will replicate the
GOOD effects of nicotine (shutting down DA production) but not the bad
(health concerns).
One drug
that is being experimented with is called ABT-418 or Mecamylamine. This
drug blocks the nicotinic receptors that would trigger the release of
dopamine to regulate blood pressure. Thus release of dopamine is inhibited,
and dopamine levels drop.
