Parkinson's Disease

Question 1

What are some symptoms of a patient suffering from Parkinson’s Disease?

Answer 1

blank facial expression
slow, monotonous slurred speech
rigidity and tremor of extremities and head
forward tilt to posture
reduced arm swinging
short, shuffling gait

Question 2

Degeneration of dopaminergic neurons projecting from the ___ ___ to the ___.

Answer 2

substantia nigra; striatum

Question 3

Normally, activation of dopamine ___ receptors (Galpha-i) in the striatum affects ___ and ___ release.

Answer 3

D2; acetylcholine; GABA

Question 4

Degeneration of dopaminergic neurons projecting to the striatum attenuates ___ release and leads to a loss of proper control of motor function.

Answer 4

dopamine

There is loss of dopaminergic input

Question 5

T/F. Dopamine can cross the blood brain barrier to get to the substantia nigra.

Answer 5

False, L-dopa, not dopamine, can cross the blood brain barrier to get to the substantia nigra.

Question 6

Why does therapy with L-dopa have the best results if obtained during the first several years of treatment?

Answer 6

Sometimes there is a need to diminish dose over time because of adverse effects
Patients become less responsive (more degeneration)

Question 7

T/F. Generally, L-DOPA treatment is good for 3-4 years.

Answer 7

True.

Question 8

What enzyme does carbidopa inhibit?

Answer 8

a PERIPHERAL dopa decarboxylase

Question 9

What reaction does carbidopa affect?

Answer 9

the conversion of Levodopa to dopamine, this gets more drug into the CNS because dopamine does not cross the BBB.

Question 10

T/F. Without carbidopa, 80% of patients experience nausea and vomiting. This is due to activation of dopamine receptors in the gut.

Answer 10

True.

Question 11

T/F. Dopamine receptor agonists are more toxic than L-DOPA and require a neuron from substantia nigra for delivery.

Answer 11

False, Dopamine receptor agonists are LESS toxic than L-DOPA and DO NOT require a neuron from substantia nigra for delivery.

Question 12

Match the Dopamine Receptor Agonists with its receptor of choice.

1. Bromocriptine
2. Pergolide
3. Pramipexole
4. Ropinirole

A. D1
B. D2
C. D3

Answer 12

1 - B
2 - A, B
3 - C
4 - B

Question 13

Dopamine is metabolized by what two enzymes?

Answer 13

1. MAO

2. COMT

Question 14

What are the MAO and COMT inhibitors?

Answer 14

MAO = selegiline, rasagiline
COMT = tolcapone, entacapone

Question 15

___ is a dopamine receptor agonists that when given alone causes marked vomiting and is administered parenterally. The vomiting can be overcome by concomitant use of the anti-sickness drug ___.

Answer 15

Apomorphine; domperidone

Question 16

Amantadine is used to treat ___, however it appears to enhance synthesis, release or reuptake of ___ from the surviving nigral neurons.

Answer 16

influenza; nigral

Question 17

What is the algorithm for Parkinson’s disease treatment?

Answer 17

1. dopamine agonist
2. levodopa + carbidopa
3. increase dose and frequency of 2
4. COMT or MAO-B inhibitors and adjunt therapy
5. Surgery

Question 18

What condition is an electrical disturbance in the brain caused by an inherited biochemical defect or a previously healed brain injury which manifests as a seizure disorder?

Answer 18

epilepsy

Question 19

___ and other anti-seizure drugs block high frequency firing of action potentials.

Answer 19

Phenytoin

Question 20

T/F. Some anti-convulsants potentiate the effects of GABA to dampen synaptic nerve impulses.

Answer 20

True.

Question 21

GABA ___ is the first step in GABA metabolism. ___ is an irreversible inhibitor of this enzyme.

Answer 21

tranaminase; Vigabatrin

Question 22

What drug is a GABA up-take inhibitor?

Answer 22

Tiagabine

Question 23

The binding of ___ causes the chloride channel to open leading to ___ of the cell. This affect is enhanced with the addition of ___, resulting in a greater entry of chloride ions making it more difficult to ___ and therefore ___ neural excitability.

Answer 23

GABA; depolarization; benzodiazepines; depolarize; reduces

Question 24

What type of drug is favored by dentists in emergency treatment of seizures?

Answer 24

Benzodiazepines: diazepam, lorazepam, clonazepam, clorazepate, clobazam, midazolam

Question 25

What type of drug binds with GABA to facilitate Cl- channel opening and although it is reasonably safe to treat epilepsy it has sedative effects that limit its utility?

Answer 25

Barbituates

Question 26

List some barbituates.

Answer 26

Phenobarbital
Mephobarbital
Metharbital
Primidone

Question 27

_-__ ___ channels are a low voltage activated channel that require hyperpolarization for ___. Drugs that block these channels in the ___ are effective anti-convulsants.

Answer 27

T-type calicum; activation; thalamus

Examples include ethosuximide, phensuximide, methsuximide, trimethadione

Question 28

___ and ___ are anti-convulsant drugs that block presynaptic voltage-gated ___ channels and are thought to diminish ___ mediated neurotransmission.

Answer 28

Gabapentin; Pregabalin; calcium; glutamate

Question 29

what drugs block the NMDA receptor?

Answer 29

felbamate, topiramate