Drugs For Parkinson Diseases

Question 1

The hallmark of parkinson’s disease is …..

Answer 1

Loss of dopaminergic neuron and presence of lewy bodies in the pars compacta of the substantia nigra of the brain

Question 2

Cardinal signs of parkinsonism disease are

Answer 2

Muscular rigidity
Bradykinesia ( Decreased movt)
Postural imbalance
Resting tremor

Question 3

The anti-psychotics and ati-emetics are dopamine receptor antagonist which can result in parkinsonism diseases like effect examples are…..

Answer 3

Antipsychotic
Haloperidol
Thorazine

Anti emetics
Metoclopramide
Prochlorperazine

Question 4

The rate limiting step in the synthesis of dopamine is ……..

Answer 4

Conversion of tyrosine to L DOPA
by tyrosine hydroxylase

Question 5

Dopamine can be metabolised by which enzymes

Answer 5

Aldehyde dehydrogenase
COMT
MOA

Question 6

The products of dopamine metabolism are

Answer 6

COMT 3MT
MAO 3,4 Ddihydroxyphenylacetic acid
ADD Homovallinic acid

Question 7

The products of dopamine metabolism are

Answer 7

COMT 3MT
MAO 3,4 Ddihydroxyphenylacetic acid
ADD Homovallinic acid

Question 8

The principles of drugs for treating parkinsonism disease are

Answer 8

Increase the concentration of dopamine
Work at the receptor

Question 9

What is the single most important agent in the treatment of dopamine

Answer 9

Levodopa L-DOPA

Question 10

Levodopa is administered………

Answer 10

Orally

Question 11

Why is levodopa best administered on an empty stomach

Answer 11

Because its absorption is limited by the rate and extent of gastric emptying.
Hence delayed by gastric emptying

Question 12

Dopamine is absorbed in what part of the intestine

Answer 12

Small intestine

Question 13

L DOPA is transported across the intestine and circle of Willis by ……

Answer 13

Aromatic amino acid transporter

Question 14

Why is CARBIDOPA administered with L DOPA

Answer 14

CARBIDOPA is a L DOPA decarboxylase inhibitor which prevents the action of L DOPA peripherally

Question 15

CARBIDOPA cannot cross the BBB T/F

Answer 15

True

Question 16

The half life of L DOPA is ……….

Answer 16

6-8 hours

Question 17

Side effects of levodopa are

Answer 17

Dyskinesia
On and off effect
Hallucinations
Vomiting that can be prevented by CARBIDOPA
Confusion

Question 18

Dopamine receptor agonist used for the treatment of parkinsonism disease is divided into classes ……….. and ………..

Answer 18

Ergot classes
Non ergot classes

Question 19

The ergot derivatives used in the treatment of parkinsonism are

Answer 19

Bromocriptine
Carbegoline
Pergolide

Question 20

The non ergot dopaminergic receptor agonist are

Answer 20

Ropinirole
Pramipexole

Question 21

Ergot derivatives of DA receptor agonist undergo extensive first pass effect with ………….. %of bioavailability

Answer 21

50%

Question 22

The half lifes of ergot derivatives DA receptor agonist are

Answer 22

Pergolide 27 hours
Bromocriptine 12-14 hours

Question 23

The non ergot derivatives DA receptor agonist are metabolised in ………

Answer 23

Liver and excreted through bile and a little unchanged excreted through urine

Question 24

The two non ergot derivatives DA agonist are newer drugs, administered orally with ……… %of bioavailability

Answer 24

50-90%

Question 25

Average half life of ergot derivatives DA receptor agonist are

Answer 25

8-24 hrs

Question 26

Bromocriptine and carbegoline elicit their strong agonist effect on .......

Answer 26

D2 Receptors

Question 27

The side effects associated with ergot derivatives DA receptor agonist occurs through.......

Answer 27

Adrenergic and serotonin receptors

Question 28

Pergolide has affinity for both D1 and D2 but stronger at .....

Answer 28

D1

Question 29

Non ergot derivatives DA receptor agonists have activity on D1 D2 D3 which is the lowest and highest

Answer 29

Lowest at D1 Maximum at D2 and D3

Question 30

The peculiarity of on-off phenomenon to dopamine receptor agonist and levodopa is

Answer 30

Levodopa can result in on and off DA agonist can be used to treat on and off phenomenon

Question 31

A side effect peculiar to pergolide is ......

Answer 31

Cardiac valvular disease

Question 32

Side effects associated with dopamine receptor agonists are

Answer 32

Nausea Vomiting Hypotension Fatigue

Question 33

A side effect associated with newer non ergot derivatives dopamine receptor agonist is

Answer 33

Somnolence

Question 34

Bromocriptine inhibit the release of glutamate from glutamatergic neuron T/F

Answer 34

True

Question 35

COMT inhibitors in clinical use are

Answer 35

Entacapone Tolcapone

Question 36

How does COMT affect the metabolism of levodopa

Answer 36

It is recruited by CARBIDOPA It results in metabolism of L DOPA preventing its decarboxylation to Dopamine

Question 37

Differences between entacapone and tolcapone

Answer 37

Entacapone Bioavailability is 35% Crosses BBB less Less hepatotoxic 2hrs half life Tolcapone Crosses BBB more 65% Bioavailability More hepatotoxic Longer half life

Question 38

Side effects of COMT inhibitors include

Answer 38

Nausea Vomiting Hypotension, confusion and Hallucinations somnolence Hepatotoxicity Diarrhoea Dry mouth Abdominal pain Back pain Discolouration of urine

Question 39

Which MAO enzyme is found centrally

Answer 39

MAO B

Question 40

The selective inhibition of which MOA is preffered in the treatment of PD

Answer 40

MAO B

Question 41

At what dose does selegiline act selectively on on MAOB

Answer 41

20mg/day

Question 42

Other drugs used in the treatment of parkinsonism disease are

Answer 42

Anti muscarinic agent Artane (trihexyphenidyl) Benztropine mesylate Diphenyhydramine Antiviral drug Amantadine