Exam 3 Flashcards
Dopamine, epinephrine, norepinephrine, and serotonin are all what?
monoamines (NT of the CNS)
Aspartate, GABA, Glutamate, and Glycine are all what?
amino acid (NT of the CNS)
Adenosine, adenosine monophosphate, and adenosine triphosphate are all what?
purines (NT of the CNS)
Dynorphins, endorphins, and enkephalins are all what?
opioid peptides (NT of the CNS)
Neurotensin, oxytocin, somatostatin, substance P, and vasopressin are all what?
nonopioid peptides (NT of the CNS)
Name two “other” neurotransmitters of the CNS?
Acetylcholine, Histamine
Which will pass through the blood brain barrier easier, lipid soluble molecules or charged/protein bound molecules and why?
lipid soluble because of the tight junctions that make up the BBB.
What are some possible adaptations of the CNS to prolonged drug exposure?
increased therapeutic effects due to adaptive changes (antipsychotics and antidepressants), decreased side effects (phenobarbital and sedation, morphine and nausea), tolerance and physical dependence
Dyskinesias such as tremor at rest, rigidity, postural instability, gait issues, bradykinesia, akinesia, autonomic disturbances, depression, psychosis, and dementia are all symptoms of what neurodegenerative disorder?
Parkinson’s Disease
Describe the pathology and cause of Parkinson’s Disease?
There is a degeneration of the neurons that supply dopamine to the striatum causing an imbalance between dopamine and acetylcholine. Excess ACh promotes GABA transmission to the globus pallidus and causes excess movement.
Recent evidence suggests which three proteins play a role in Parkinson’s Disease? Which one is toxic to dopaminergic neurons?
alpha-synuclein is the one that is toxic to dopaminergic neurons. Parkin and ubiquitin are the two proteins that are involved in breaking down alpha-synuclein. If any of these three proteins are defective then alpha-synuclein accumulates in the cell forming neurotoxic fibrils called lewy bodies.
What are the two major categories of drugs used to treat Parkinson’s disease?
dopaminergic agents and anticholinergic agents
This dopaminergic agent is used to treat PD and promotes dopamine synthesis, often given in combination with carbidopa.
levodopa
These dopaminergic agents stimulate dopamine receptors directly, examples include Pramipexal (Mirapax) and Apomorphine.
dopamine agonists
This dopaminergic agent inhibits dopamine breakdown, Selegine (Eldepryl and Carbex) are examples.
MAO-B inhibitor
This dopaminergic agent promotes dopamine release.
Amantadine
These dopaminergic agents block the degradation of levadopa, an example is Entacapone (Comtan).
COMT inhibitors
This drug used for PD crosses the blood brain barrier and is then converted to dopamine by the enzyme decarboxylase pyridone. It can be degraded in the brain, liver, and intestine.
Levodopa
Nausea and vomiting due to the presence of DA-R in the CTZ, Dyskinesia, dysrhythmias, hypotension, psychosis in 20% of patients, dark urine and sweat, malignant melanoma, and the need for drug holidays are all adverse reactions of which PD med?
Levodopa
Why are Carbidopa and Levodopa often given together and what are the advantages and disadvantages of this?
The Carbidopa prevents decarboxylation of Levodopa in the periphery, making more of it available in the brain. this decreases the amount of levodopa needed for a therapeutic response. The disadvantage is that abnormal movements and psychiatric disturbances appear sooner.
How do Carbidopa, Tolcapone, and Entacapone increase the effects of Levadopa?
By inhibiting its metabolism.
How do Bromocriptine and Pramipexole increase the effects of Levadopa?
By directly stimulating dopamine receptors.
How does Amantadine increase the effects of Levadopa?
By promoting the release of dopamine.
How do anticholinergic drugs increase the effects of Levadopa?
By blocking CNS acetylcholine receptors.