Drugs for Parkinson's Disease Flashcards Preview

Pharmacology > Drugs for Parkinson's Disease > Flashcards

Flashcards in Drugs for Parkinson's Disease Deck (13):
1

1. Akinesia
2. Bradykinesia

1. Difficulty initiating movement
2. Slowness of movement

2

3 general ways to treat Parkinsons

1. Drugs that increase DA levels in the brain
2. DA receptor agonists
3. Acetylcholine Antagonists

3

Drugs that increase DA levels

Levodopa (L-DOPA)
Precursor of DA
Can cross the BBB (unlike DA) and is taken up by neurons in the substantia nigra (where it is converted to DA by DDC)
Adverse effects: nausea, orthostatic hypotension, cardiac arrhythmias - due to increase catecholamines in peripheral tissues

4

Dopa decarboxylase Inhibitor

Ex: Carbidopa
Analog of L-DOPA
Inhibits conversion of L-DOPA to DA in peripheral tissue
Does NOT cross the BBB
Need combo with L-DOPA

5

Catechol-O-methyltransferase (COMT) inhibitors

Ex: Entacapone, tolcapone
Block conversion of L-DOPA to 3-OMD which may compete for CNS uptake
Used in combo with L-DOPA
Inhibits activity of COMT
Maximizes the bioavailability of L-DOPA to go into brain

6

Selegiline

Irreversible inhibitor of MAO-B in the striatum
Striatal MAO-B metabolizes DA
Inhibits oxidation of DA to DOPAC (increase DA levels in striatum

7

Dopamine Receptor Agonists

Directly activate DA receptors (bromocriptine, pramipexole)
Can be used in combo with L-DOPA/carbidopa
Act at post synaptic DA receptors
Activation of specific DA receptors may limit adverse effects of these drugs

8

Antimuscarinic Drugs

Block striatal muscarinic receptors (benztropine)
Not as effective as L-DOPA/carbidopa treatment
Efficient in control of tremors
Often used in combo therapy
Alleviate extrapyramidal effects caused by older anti-psychotic drugs

9

Amantadine
(3 proposed mechanisms)

Often used with L-DOPA/carbidopa therapy
Also an anti-viral drug
Used in patients who dont respond well to L-DOPA
Proposed mechanisms of action: Inhibits DA re-uptake, facilitate pre-synaptic DA release, antagonise NMDA receptors

10

Bromocriptinie and pramipexole

DA agonists

11

Selegiline

MAO inhibitors

12

Entacapone, tolcapone

COMT inhibitors

13

Benztropine

Muscarinic Antagonists