Parkinson Med Chem Flashcards
The molecule on the left is known as ___ and the molecule on the right is known as ___.
A. Dopamine, Levodopa (L-Dopa)
B. Carbidopa, Levodopa (L-Dopa)
C. Dopamine, Carbidopa
D. Carbidopa, Dopamine
A. Dopamine, Levodopa (L-Dopa)
The medication Levodopa (Dopar) is metabolized by ___ in order to produce dopamine
A. Carboxylic Dehydrogenase (CD)
B. Dopa Decarboxylase (DD)
C. Dopa Hydroxylase (DH)
D. Carboxylic Decarboxylase (CD)
B. Dopa Decarboxylase (DD)
Which of the folowing statements regarding levodopa (L-Dopa) is true?
A. Highly bioavailable
B. Able to cross the BBB easily
C. Little-to-no side effects
D. Low bioavailability
D. Low bioavailability
Only about 1-2% of the medication is able to cross the BBB
What transporter does levodopa use to cross into the brain?
A. GABA-specific transporters
B. L1-Transporters
C. COMT transporters
D. L5-Transporters
B. L1-Transporters
The issue with L-Dopa crossing into the BBB by way of the L1 transporter is that the transporter is easily ___ by other substrates for that transporter.
A. Antagonized
B. Inactivated
C. Saturated
D. Opened
C. Saturated
Levodopa is one of the many substrates that use the L1-Transporter and as a result the transporters can be easily occupied by other molecules. This limits the amount of levodopa that is able to get through the transporter since it must compete with other molecules.
Carbidopa is known as a ___ derivative of Levodopa (L-Dopa).
A. Hydrazine
B. Hydroxyzine
C. Hydrazyl
D. Piperazine
A. Hydrazine
The green group in Carbidopa is known as a Hydrazine
(Short Answer)
What is the purpose of Carbidopa when it is given with Levodopa?
Carbidopa resembles Levodopa with the exception of the hydrazine group that is added. The benefit of this is that the carbidopa will instead inhibit the Dopa Decarboxylase (DD) from converting Levodopa to Dopamine in the periphery. Essentially, it acts as a decoy for Levodopa and allows it more time to pass into the BBB.
Which of these is used in the case of a Levodopa overdose?
A. NAC
B. B12
C. B6- Pyridoxine HCl
D. Vitamin K
C. B6- Pyridoxine HCl
Vitamin B6 is considered to be a(n) ___ for Dopa Decarboxylase (DD) and can enhance its activity in the case of Levodopa overdoses.
A. Enzyme
B. Enhancer
C. Synergizer
D. Cofactor
D. Cofactor
Giving the dopamine agonist, Bromocriptine (Parlodel) with Levodopa allows you to give Levodopa at ___ doses.
A. Higher
B. Lower
B. Lower
Advantage: Dose reduction in levodopa
What type of enzymes are used when metabolizing Bromocriptine?
A. Esterases
B. Hydroxylases
C. Reductases
D. COMT
A. Esterase
If you look at the area where bromocriptine is being cleaved you will notice that it is an Amide. An Amide is an ester-derivative so when the bond is cleaved it will be cleaved by esterases.
Which of the following are problems with giving Dopamine itself as a treatment for Parkinsons Disease? (Select All)
A. Dopamine is highly lipophilic and can cross the BBB easily and cause toxic effects even at low doses.
B. Dopamine is easily ionizable in the periphery at physiological pH and wil not cross the BBB.
C. Dopamine will autooxidize and form Quinone-like metabolites that are neurotoxic
D. When metabolized dopamine produces metabolites that exhibit long half-lives and can cause toxic dopaminergic effects.
B. Dopamine is easily ionizable in the periphery at physiological pH and wil not cross the BBB.
C. Forms active Quinone-like metabolites that are neurotoxic
The following picture shows the neurotoxic quinone-like species that are formed when dopamine is metabolized in the periphery.
Apomorphine contains a chiral carbon and exhibits isomerism. Which Isomer is sold as the drug itself?
A. S-(+)-isomer
B. R-(-)-isomer
B. R-(-)-isomer
The dopamine agonists Pramipexole (Mixapex) and Ropinirole (Requip) contain a(n) __ core that resembles dopamine.
A. Benzyl
B. Aromatic ether
C. Phenylethylamine
D. Catechol
C. Phenethylamine
Phen- Phenyl ring
Ethyl- Two carbons
Amine- Nitrogen group
PhenEthylAmine
They are also D2/D3 agonists
Rotigotine (Neupro) is a dopamine agonist that exhibits a low oral bioavailability. As a result it is given as a(n)___.
A. IV injection
B. Transdermal
C. IM injection
D. SubQ
B. Transdermal
