CNS AntiParkinsonism Drugs

Question 1

Parkinsonism
Parkinson disease

Answer 1

Parkinsonism = It is an extrapyramidal motor disorder characterized by rigidity , tremor , bradykinesia

Parkinson’s Disease = It is a progressive disorder of movement that occurs. The elderly commonly associated with dementia

Question 2

Biological basis of Parkinsonism

Answer 2

Decrease dopamine concentration
Increase cholinergic activity
So imbalance between Dopeaminergic and cholinergic activity

Question 3

Why Levo dopa is combinely with carbidopa

Answer 3

Normally , Levodopa is converted into dopamine in the periphery , 70% by Dopa decarboxylase (DDC) enzyme and this dopamine caused more adverse effects in the periphery . Only 1-3% L. Dopa crosses blood brain barrier.

But when L.dopa is combinely used with carbidopa

Carbidopa is a peripheral DDC enzyme inhibitor. So, L dope is not converted into dopamine in the periphery and more L. Dopa is available at the periphery which ultimately crosses BBB and converted in dopamine in the brain by brain DDC enzyme so it increases dopamine concentration in the brain and correction of Parkinsonism disease

Question 4

A/E of levodopa

Answer 4

Anorexia
Anxiety
Nausea
Vomitting
Tachycardia
Insomnia
Hallucination
Delusion
Confusion
Nightmare
Euphoria

Question 5

Drugs responsible for Parkinsonism

Answer 5

Haloperidol
Chlorpromazine
Methyldopa
Reserpine
Metochlorpromide
Valporic acid

Question 6

Drugs used for Parkinsonism

Answer 6

A] INCREASE DOPAMINE CONCENTRATION

1) Dopamine precursor = Levodopa
2) Dopamine agonist = Bromocriptin , Ropinirole , Pergolide , Pramipexole

B] INCREASE DOPAMINE SYNTHESIS , RELEASE
Amantadine

C] DECREASE DOPAMINE METABOLISM
Rasagiline
Selegiline MAO inhibitor
Tolcapone
Entacapone

D] DRUGS THAT DECREASE ANTIMUUSCARINIC ACTIVITY
Procyclidine
Benztropine
Benzhexol
Biperidine