Drugs In Neuropathology

Question 0

L-dopa pharmacokinetics

Answer 0

Oral
Compete with amino acids for transporter uptake, so don’t take with high protein meals
T1/2 2 hrs, so take tablets regularly
9% converted to dopamine in peripheral tissue, so give with a dopa decarboxylase inhibitor
<1% effective

Question 1

L- dopa uses

Answer 1

Used in Parkinson’s
Crosses the BBB
Is then converted to dopamine

Question 2

L dopa pros

Answer 2

Effective

Few side effects

Question 3

L dopa cons

Answer 3

Needs enzyme inactivation

Get wearing off, on/off, dyskinesia, dystonia, freezing

Question 4

L dopa ADRs

Answer 4

Nausea/anorexia
Hypotension
Tachycardia
Psychosis

Question 5

L dopa DDIs

Answer 5

Antipsychotics - have parkinsonian side effects
MAOIs- risk hypertensive crisis
Pyridoxine (vit B6) increases peripheral breakdown

Question 6

Dopamine receptor agonists uses

Answer 6

De novo or add on therapy in Parkinson’s

Question 7

Bromocryptine
Pergolide
Cabergoline

Answer 7

Ergot derived dopamine receptor agonists

Rarely used due to side effect profile

Question 8

Ropinerole

Pramipexole

Answer 8

Non Ergot derived dopamine receptor agonists

Question 9

Rotigotine

Answer 9

Dopamine receptor agonist that can be given by patch

Question 10

Apomorphine

Answer 10

Dopamine receptor agonist that can be given subcutaneously, but only for patients with severe motor fluctuations

Question 11

Dopamine receptor agonist pros

Answer 11

Possible neuroprotection
Less motor complications
Direct action

Question 12

Dopamine receptor agonist cons

Answer 12

Less efficacy than L-dopa
Impulse control disorders
Expensive
More psychiatric side effects

Question 13

Dopamine receptor agonist ADRs

Answer 13

Sedation
Nausea
Confusion
Hypotension
Hallucination

Question 14

Monoamine oxidase B inhibitors uses

Answer 14

Prevents dopamine metabolism
Increases dopamine 
Can be used alone or to prolong L dopa action 
Smooths out motor response 
May be neuroprotective

Question 15

Selegine

Rasagiline

Answer 15

Monoamine oxidase B inhibitors

Question 16

Catechol-o-methyl transferase inhibitors uses

Answer 16

Prolong motor response to L dopa by preventing peripheral breakdown
No therapeutic effect alone

Question 17

Tolcapone

Answer 17

Catechol-o-methyl transferase inhibitor

Can cross BBB but main effects are peripheral

Question 18

Entacapone

Answer 18

Catechol-o-methyl transferase inhibitor

Doesn’t cross BBB

Question 19

Anticholinergic uses in Parkinson’s

Answer 19

ACh can antagonise dopamine
Minor role in treatment
Reduces tremor
No effect on bradykinesia

Question 20

Trihexyphenidyl
Orphenadrine
Procyclidine

Answer 20

Anticholinergics used in Parkinson’s

Question 21

Anticholinergics in Parkinson’s ADRs

Answer 21

Usual anticholinergic profile

Confusion, drowsiness

Question 22

Amantidine

Answer 22

Used in Parkinson’s
Mechanism uncertain
Poorly effective
Few side effects

Question 23

Surgery in Parkinson’s

Answer 23

Lesion -thalamus for tremor, GPi for dyskinesia

DBS - subthalamic nucleus

Question 24

Acetylcholinesterase inhibitor uses

Answer 24

Myasthenia gravis

Question 25

Neostigmine

Answer 25

Acetylcholinesterase inhibitor

Oral or IV

Question 26

Pyridostigmine

Answer 26

Acetylcholinesterase inhibitor
T1/2 4-6 hours
Oral

Question 27

Acetylcholinesterase inhibitor ADRs

Answer 27

Lacrimation
Salivation
Emesis 
Sweating 
Urinary incontinence
Diarrhoea 
Over treatment causes cholinergic crisis