DRUGS

Question 1

Which drugs affect dopamine inactivation?

Answer 1

• MOAb inhibitors
• COMT inhibitors
• antimuscarinic drugs

Question 2

MOAb inhibitors - examples of mechanism of action

Answer 2

Selegilline
Rasagiine
- stop dopamine being broken down in pre-synaptic neurons (dopamine to DOPAC)

Question 3

COMT inhibitors

Answer 3

Entacapone
Tolcapone
- stop dopamine degradation from DOPAC to homovanillic acid
- may also help alleviate L-Dopa side effects so can use for loner

Question 4

Antimuscarinics

Answer 4

aAntagonists of muscarinic acetylcholine receptors, increasing dopamine release and inhibiting re-uptake

• benzhexol
• benztropine

Question 5

Which drugs affect dopamine storage?

Answer 5

• reserpine
• tetrabenazine
• amantadine

Question 6

Amantadine

Answer 6

Increases release of dopamine from monoaminergic terminals through inhibiting amine uptake, MOA activity

Question 7

Which drugs decrease release of dopamine?

Answer 7

Reserpine
Tetrabenazine
- inhibit vesicular storage of dopamine by irreversibly inhibiting VMAT2 (vesicular monoamine transporter)

Question 8

Which drugs affect dopamine synthesis?

Answer 8

Madopar
L-Dopa
Alpha methyl-p-tyrosine

Question 9

Alpha methyl-p-tyrosine

Answer 9

Competitive inhibitory of dopamine

- inhibits tyrosine hydroxylase so synthesis rate limiting step (tyrosine-> DOPA)

Question 10

Madopar

Answer 10

L-DOPA + benserazide (peripheral decarboxylase inhibitor) preventing L-DOPA to dopamine conversion outside of the BBB as benserazide cannot get through the BBB

Question 11

Which drugs are post synaptic dopamine receptor agonists?

Answer 11

Pergolide
Quinpirole
Bromocriptine
Apomorphine
Rotigotine

Question 12

Pergolide and quinpirole

Answer 12

D1 and D2 non selective agonists

Question 13

Bromocriptine

Answer 13

High D2 affinity, dopamine agonist

Question 14

Apomorphine

Answer 14

Non selective dopamine agonist potent emetic, infusion

Question 15

Rotigotine

Answer 15

Non-selective dopamine agonist transdermal patch

Question 16

Which drugs are post synaptic dopamine receptor antagonists?

Answer 16

Chlorpromazine
Haloperidol
Spiperone
Sulrpide
Clozapine

(used to treat schizophrenia, high D2 affinity)

Question 17

Anticholinergics

Answer 17

As loss of dopamine = increased activity

-orphenadrine and procyclidine

Question 18

L-DOPA

Answer 18

Levodopa

Carbidopa