• Which two main groups of drugs are important in the treatment of Parkinsonism?

Drugs that increase Dopamine Activity ( L-dopa and dopamine agonists)

Drugs that decrease Anti-cholinergic Activity (Anti cholinergic)

• In what way does amantadine act as an antiparkinsonism drug?

It serves as a mettafinoid Potentiator of Dopamine by increasing its release and synthesis and blocking its reuptake. It further acts as an adenosine A2 Antagonist as well as an NMDA Antagonist.

• Discuss the mechanisms of action of the antiparkinsonism drugs that indirectly increase dopamine concentration.

MAO-B Inhibitors work to increase extracellular Dopamine levels in the striatum by suppressing metabolism

COMT-Inhibitors work to inhibit COMT in the periphery thus decreasing peripheral metabolism as it inhibits the formation of 3-OMD.

• Which of the dopamine agonists are ergot derivatives and which are not?

Ergot derivative: Bromocriptine 

Non-ergot derivative: Pramipexole and Ropinirole

• List the specific dopamine receptors that are stimulated by each agonist.

Bromocriptine and Ropinirole: D2 Agonist

Pramipexole: D3 Agonist

• Which of these drugs are classified as neuron protecting drugs? What does this mean?

Drugs such as Rasagiline are seen as neuroprotective as they prevent the degeneration of dopamine neurons due to constant stimulation

• What is the importance of monoamine oxidase B (MAO-B) selective drugs in the treatment of Parkinsonism?

These drugs allow for Dopamine neurons to be constantly stimulated without allowing for degeneration as they are neuroprotective.

• How do the COMT-inhibitors act in Parkinsonism?

These drugs extend the action of L-dopa by decreasing the peripheral metabolism and increasing the bioavailability of dopamine and inhibiting the formation of the 3-OMD metabolite.

• How does Istradephyline act?

It functions as an adenosine A_2A Antagonist by blocking the adenosine receptor, improve D2 function & also acts as an antiviral

• Discuss the MOA of safinamide

It increases the activity of dopamine as it is a potent reversible MAO-B inhibitor an inhibits dopamine re-uptake .It also decreases glutamate release.