Parkinsons Drugs

Question 1

Dopaminergic

Carbidopa levodopa

Answer 1

MOA: dopamine replacement

Lower effectiveness after 5 years

When levodopa is alone, only 1% reaches the brain
99% converts to dopamine while in the PNS

You will need carbidopa to inhibit conversion of levodopa to dopamine so more can cross the BBB and reach the brain

Short duration so must take frequent doses
People who are taking it sometimes have exaggeration of Parkinson’s when the wearing off period happens

Question 2

Side effect of dopaminergic drug

Answer 2

Dystonia : involuntary abnormal stiffness, twisting

Dyskinesia: involuntary abnormal movements

Akathisia: urge to move constantly

Psychosis: hallucinations, nightmares, paranoia

Peripheral nervous system effects: “ Bear”

Brown discoloration of urine 
Activates vomiting center in brain
Avoid B6 (cereals, meat, fish ) 
Malignant melanoma
Leukopenia (low wbc which Is a weak immune system) or thrombocytopenia (low platelets so at risk for bleeding )

Question 3

Dopamine Agonists

Amantadine

Answer 3

MOA: improve dopamine action

Also anti viral for flu A

Drug tolerance develops , do not discontinue abruptly

Question 4

Dopamine agonists side effects

Answer 4

Live do recticularis ( temp skin discolor )

Anticholinergic effects (bear)

Question 5

Anticholinergics

Benztropine

Answer 5

MOA: inhibit release of acetylcholine in CNS

Side effects: bear
Dystonia

Contraindication: history of Alzheimer’s or MG