Anti-Parkinsons, Anti-convulsants, and drugs to treat bipolarism Flashcards
What is the concept of ‘threshold’ in neurodegenerative diseases?
Everyone will suffer some sort of neural degeneration with age, but once it reaches a certain threshold it is determined a disease
What happens neurobiologically to cause Parkinson’s?
Degeneration of dopaminergic neurons projecting from the substantia nigra to the striatum - don’t get enough dopamine
Normally, activation of what affects acetylcholine and GABA release?
Dopamine D2 receptors
The degeneration of dopaminergic neurons to the striatum does what?
Attenuates dopamine release, leading to improper control of motor function
What is the aim of the treatment of Parkinsons?
Overcoming the loss of dopanergic input
What does L-DOPA treatment do?
Remaining projections to the striatum provide more dopamine to the synapse
Does not cross the BBB
When are the best results for L-DOPA treatment?
Why?
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?)
What is typically given with L-DOPA?
Why?
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
What are some advantages of giving Dopamine Receptor Agonists?
They’re not as toxic as L-DOPA
Don’t require neuron from the substantia nigra for delivery
What can Metabolic Enzyme Inhibitors do for Parkinson’s treatment?
Lengthen the time dopamine works
What are examples of Metabolic Enzyme inhibitors to treat Parkinson’s?
MAO
COMT
Apomorphine
A harsh treatment for Parkinson’s
Given parenterally
Requires considerable nursing support but can eb effective
What are the two types of Epilepsy?
Idiopathic Epilepsy
Acquired Epilepsy
Idiopathic epilepsy
An electrical disturbance in the brain caused by an inherited biochemical defect which manifests as a seizure disorder
Acquired epilepsy
An electrical disturbance in the brain caused by a previously healed brain injury which manifests as a seizure disorder
T/F - there are different types of epileptic seizures
True
What does phenytoin do?
Blocks high frequency firing of action potentials
Block Na channels in their open resting state (much like local anesthetics)
What are the different ways Anti-seizure drugs work?
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) ???
How does GABA prevent seizures?
Causes hyperpolarization by activating Cl influx, preventing postsynaptic APs
What are the mechanisms of GABA potentiation
1) Inhibit GABA transaminase
2) Inhibit GABA uptake
3) Facilitate Cl channel opening
What is tiagabine?
GABA uptake inhibitor
What drug is favored by dentists in emergency treatment of seizures?
Benzodiazepines
How do Benzodiazepines work?
They facilitate Cl channel opening
Pharmacological treatment of epilepsy achieves effective control for how many of those effected?
80%
T/F - Most drugs used to treat epilepsy only have one mechanism of action
False - many have multiple mechanisms of action
What is the implication of anti-convulsants on dentistry?
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
What is the main drug to treat bipolar disorder?
Lithium
How do lithium salts work?
not sure, but it’s a mood stabalizer….so we have that going for us.
