Neuro exams - Parkinson's, Epilepsy and Glaucomo Flashcards Preview

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Flashcards in Neuro exams - Parkinson's, Epilepsy and Glaucomo Deck (35)
1

What is the pathophysiology of parkinson's disease?

o Loss of Dopaminergic Neurones from the pars compacta of the Substantia Nigra in the midbrain that project to the striatum of the basal ganglia.

2

GIve main treatment for Parkinson's and five adjuvants

Levodopa (L-DOPA)
o Dopamine receptor agonists
o MAOI Type B inhibitors
o COMT inhibitors
o Anticholinergics
o Amantadine

3

When is L-dopa used?

Immediate precursor of dopamine and is able to penetrate the BBB to replenish the dopamine lost in the neostriatum

4

Give four of the main ADRs of L-dopa

 Nausea and vomiting
 Hallucinations, delusions (schizophrenia)
 Cardiovascular effects (hypotension)
 Dyskinesia

5

What does L-dopa have to be given with in order to prevent its breakdown?

Periperhal DOPA dexcarboxylase inhibitor

6

What kind of drugs can cause parkinson's like symptoms?

Anti-psychotic drugs

7

Why do you need to give a large dose of L-dopa?

Large amount of peripheral breakdown

8

What is the mechanism of dopamine receptor agonists?

Agonist for D2 receptors

9

What are some ADRs for dopamine receptor agonists?

 Sedation, hallucination, confusion
 Nausea
 Hypotension
 Psychiatric symptoms

10

What do monoamine oxidase type B inhibitors do?

selectively inhibits the MAOB enzyme in the brain that is normally responsible for the breakdown of dopamine. By inhibiting breakdown, the dose of L-DOPA is prolonged.

11

What are three ADRs for MAOIs

Hypertension
Sympathetic response
Psychiatric symptoms

12

What do COMT I inhibitors do?

 Inhibits the enzyme COMT, which degrades L-dopa in the periphery. No therapeutic effect alone.
 Potentiates effects of L-dopa

13

Give three ADRs of COMT

 Nausea and Vomiting
 Abdominal pain
 Diarrhoea

14

How do anti-cholinergics work in parkinsons?

 Antagonists at the muscarinic receptors that mediate striatal cholinergic excitation
 Acetylcholine -> Antagonistic effect on dopamine
 Main action in treatment of Parkinson’s disease is to reduce excessive striatal cholinergic activity

15

Give two ADRs of anti-cholinergics

 CNS effects – Mild memory loss, acute confusional states
 Dry mouth and blurred vision (less common)

16

What does amantadine do?

 Stimulates neuronal dopamine release and inhibition of its reuptake
 Additional muscarinic blocking actions

17

Give three ADRs of amantadine?

 Anorexia
 Nausea
 Hallucinations

18

What is the treatment in myasthenia gravis?

Acetylcholinesterase inhibitors

19

CRANIAL NERVES What do acetylcholinesterase inhibitors do?

Prevent breakdown of Ach in synaptic cleft

20

What is the major ADR of acetylcholinesterase inhibitors

Muscarinic side-effects
SSLUDGE syndrome

21

What is another treatment for myasthenia gravis?

Plasmaphoresis
Removes AchR antibodies and gives short term improvement

22

What drug should not be given in Myasthenia gravis?

ACE inhibitor
- Myasthenic crisis
- Cholinergic crisis

23

What is SSLUDGE syndrome?

Salivation
Sweating
Lacrimation
Urinary incontinence
Diarrhoea
GI upset
Emesis

24

What is the mechanism of action for lamotrigine?

 Prolongs VGSC inactivation state

25

Give some DDIs for lamotrigine

 Adjunct therapy with other anti-epileptic drugs
 Oral Contraceptives reduce Lamotrigine plasma levels
 Valproate increases Lamotrigine plasma levels (protein binding)

26

Give some ADRs for lamotrigine

Dizziness, ataxia, drowsiness

27

What is the mechanism of action of sodium valproate?

 Weak inhibition of GABA inactivation enzymes   GABAA
 Weak stimulus of GABA synthesising enzymes   GABA A
 Weak VGSC blocker and Weak Ca2+ channel blocker   Discharge

28

Give three ADRs for sodium valproate

Ataxia, tremor, weight gain

29

What is a big DDI for sodium valproate?

Displaces other AED (lamotrigine and phenytoin), increasing concentration

30

When is carbamezapine used?

Status epilepticus/second line in others

31

What is mech of action of carbamezapine?

Voltage gated sodium channel blocker

32

Give a couple of adverse drug reactions of carbamezapine?

Dizziness, drowsiness
Hyponatraemia

33

What is the major cause of DDIs in carbamezapine treatment?

CYP450 Enzyme inducer
(PCBRAS)

34

Why should phenytoin dose be carefully monitered?

Non-linear, can reach toxic doses quickly

35

What can cause horner's syndrome?

Apical Lung Tumour
Lower brachial plexus injury