So let's wrap up this look.
Parkinson's disease is a progressive nervous system disorder that affects a person's ability to control movement.
There's an imbalance, remember?
There's an imbalance in the neurotransmitter’s acetylcholine and dopamine.
Dopamine cannot cross the blood-brain barrier by itself
and levodopa is not dopamine but it does increase the dopamine synthesis in the striatum.
Remember we have an active transport system that carries levodopa over the blood-brain barrier
and so it increases the dopamine synthesis in the striatum
because that's where it turn it into dopamine.
Carbidopa -- super cool -- levodopa's best friend
because it slows down the breakdown of levodopa in the gut and peripheral tissues.
Remember that fancy term decarboxylation.
Now levodopa plus carbidopa allows for a 75% reduction in the amount of levodopa
that we have to give a patient and that's a really good thing because over time,
the effects of levodopa and carbidopa will diminish.
Most effective for the first two years and then progressively declines after three to five years.
Now the drug does really good things but it can also cause more problems
that sometimes it's hard to tell the difference between the drug or the disease.
So, the patient can develop dyskinesias, difficulty in movement from the medication.
Be careful not to have large amounts of dietary protein with the levodopa
because the medication will compete for protein transport sites across the blood-brain barrier.
So, the medication will be a less effective if the patient eats a high protein meal
at the same time, they take the levodopa/carbidopa.
Now the adverse effects of levodopa are sadly a little long, right?
We have CNS, behavior changes, sleep disturbances, irregular heartbeat, low blood pressure,
nausea, vomiting, diarrhea, darkening of their body fluids like urine, sweat and saliva,
and it could activate melanoma.
They can also induce the dyskinesias so we wanna use it only in caution with first generation antipsychotics
and I mean extreme caution with first generation antipsychotics.
Like there would have to be a really good reason that you're doing that with very close monitoring
and you would not want to give it with MAOI inhibitors.
Now, anticholinergic medications will help us increase the effectiveness in dopamine in the brain. Why?
Because it blocks those acetylcholine receptors so even though we have extra acetylcholine,
by blocking off those receptors it won't be able to wreck its havoc.
We can even the odds between acetylcholine and dopamine imbalance in the brain.
Thank you for watching our video today.