Anti-Parkinsons, Anti-convulsants, and drugs to treat bipolarism

Question 1

What is the concept of ‘threshold’ in neurodegenerative diseases?

Answer 1

Everyone will suffer some sort of neural degeneration with age, but once it reaches a certain threshold it is determined a disease

Question 2

What happens neurobiologically to cause Parkinson’s?

Answer 2

Degeneration of dopaminergic neurons projecting from the substantia nigra to the striatum - don’t get enough dopamine

Question 3

Normally, activation of what affects acetylcholine and GABA release?

Answer 3

Dopamine D2 receptors

Question 4

The degeneration of dopaminergic neurons to the striatum does what?

Answer 4

Attenuates dopamine release, leading to improper control of motor function

Question 5

What is the aim of the treatment of Parkinsons?

Answer 5

Overcoming the loss of dopanergic input

Question 6

What does L-DOPA treatment do?

Answer 6

Remaining projections to the striatum provide more dopamine to the synapse
Does not cross the BBB

Question 7

When are the best results for L-DOPA treatment?

Why?

Answer 7

First 3-4 years of treatment
Sometimes we need to diminish the dose over time because of adverse effects
Patients become less responsive (may because of more degeneration?)

Question 8

What is typically given with L-DOPA?

Why?

Answer 8

Carbidopa (peripheral dopa decarboxylase inhibitor)
It gets more drug into the CNS
Without carbidopa, 80% of patients experience nausea and vomitting, because it diminishes the effect of dopamine receptors in teh gut

Question 9

What are some advantages of giving Dopamine Receptor Agonists?

Answer 9

They’re not as toxic as L-DOPA

Don’t require neuron from the substantia nigra for delivery

Question 10

What can Metabolic Enzyme Inhibitors do for Parkinson’s treatment?

Answer 10

Lengthen the time dopamine works

Question 11

What are examples of Metabolic Enzyme inhibitors to treat Parkinson’s?

Answer 11

MAO

COMT

Question 12

Apomorphine

Answer 12

A harsh treatment for Parkinson’s
Given parenterally
Requires considerable nursing support but can eb effective

Question 13

What are the two types of Epilepsy?

Answer 13

Idiopathic Epilepsy

Acquired Epilepsy

Question 14

Idiopathic epilepsy

Answer 14

An electrical disturbance in the brain caused by an inherited biochemical defect which manifests as a seizure disorder

Question 15

Acquired epilepsy

Answer 15

An electrical disturbance in the brain caused by a previously healed brain injury which manifests as a seizure disorder

Question 16

T/F - there are different types of epileptic seizures

Answer 16

True

Question 17

What does phenytoin do?

Answer 17

Blocks high frequency firing of action potentials

Block Na channels in their open resting state (much like local anesthetics)

Question 18

What are the different ways Anti-seizure drugs work?

Answer 18

1) Block high frequency firing of APs
2) Potentiate GABA
3) Blockade of T-type Ca channels
4) Block voltage gated Ca channels
5) Blockade of NMDA receptors
6) ???

Question 19

How does GABA prevent seizures?

Answer 19

Causes hyperpolarization by activating Cl influx, preventing postsynaptic APs

Question 20

What are the mechanisms of GABA potentiation

Answer 20

1) Inhibit GABA transaminase
2) Inhibit GABA uptake
3) Facilitate Cl channel opening

Question 21

What is tiagabine?

Answer 21

GABA uptake inhibitor

Question 22

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

Answer 22

Benzodiazepines

Question 23

How do Benzodiazepines work?

Answer 23

They facilitate Cl channel opening

Question 24

Pharmacological treatment of epilepsy achieves effective control for how many of those effected?

Answer 24

80%

Question 25

T/F - Most drugs used to treat epilepsy only have one mechanism of action

Answer 25

False - many have multiple mechanisms of action

Question 26

What is the implication of anti-convulsants on dentistry?

Answer 26

1) Develop an emergency plan to deal with patients who start to convulse
2) Your emergency cart should include Benzodiazepene
3) Know how to use anti-convulsants

Question 27

What is the main drug to treat bipolar disorder?

Answer 27

Lithium

Question 28

How do lithium salts work?

Answer 28

not sure, but it’s a mood stabalizer….so we have that going for us.