Module 9: Meds For Neurodegenerative And Seizure Disorders Flashcards
What is the main inhibitory neurotransmitter?
GABA (gamma-aminobutyric acid)
How does GABA work?
works by decreasing brain activity.
Although different classes of CNS depressants work in unique ways, ultimately it is their ability to increase GABA activity that produces a drowsy or calming effect.
What is the inhibitory neurotransmitter which maintains mood balance?
Serotonin
What is the inhibitory and excitatory neurotransmitter which regulates movement and emotional response? Also helps to regulate reward and pleasure centres in the brain
Dopamine
What is the neurotransmitter which has an excitatory action related to mood, motor activity, arousal and reward?
Norepinephrine
Neurotransmitter whose excitatory action regulates movement and memory?
Acetylcholine
What is Parkinson’s disease?
Degenerative disorder of the CNS caused by death of the neurons that produce dopamine
What is the underlying neurotransmitter imbalance in PD?
Lack of dopamine activity and a related hyperactivity of acetylcholine
What is PD characterized by?
tremors, muscle rigidity, bradykinesia (slowness of movements, poor fine motor skills), postural instability, limb stiffness, difficulties with gait and balance
What are the goals of pharmacotherapy to manage PD?
Restore dopamine function (Dopamine Agonists)
Block the effect of ACh (Anticholinergics)
What is the drug of choice for Parkinson’s disease?
Levodopa, enhanced by combination with carbidopa (Sinemet)
Why is dopamine not used for therapy for PD?
Dopamine cannot cross the blood brain barrier, levodopa can
Dopaminergics - Muscle twitching and mood changes may indicate what?
Toxicity
What is the role of anticholinergics in managing PD?
Decrease the activity of acetylcholine
- Not as effective as other agents, therefore mostly used in early onset PD
- Mainly used to control tremor and ease dystonia
Example: benztropine (Cogentin)
What class of drug is most widely used for treatment of Alzheimer’s disease?
Acetylcholinesterase (AChE) inhibitors (indirect
acting cholinergics)
- intensifies the effect of acetylcholine at the cholinergic receptors
Drug therapy for Alzheimer’s disease focusses on…
Restoring or enhancing acetylcholine’s role in the brain
Multiple sclerosis is a neurodegenerative disease characterized by
Demyelination (destruction or removal of the Myelin sheath from a nerve or nerve fibre)
What is a seizure?
A disturbance of electrical activity in the brain that may affect consciousness, motor activity, and sensation
- symptoms are caused by abnormal or uncontrollable neuronal discharges within the brain
What tool is used in diagnosing seizure disorders?
EEG
There are three general mechanisms by which anti-seizure medications act to suppress neuronal activity to prevent abnormal firing:
1) Increase the action of GABA
2) Delay an influx of sodium ions
3) Delay an influx of calcium ions (not covered in this course)
Anticovulsants: How do barbiturates work? what are the side effects?
• Enhances the inhibitory neurotransmitter GABA, thereby depressing CNS
-Low margin of safety, considered a controlled substance
• Adverse/side effects: Respiratory depression, sedation, confusion (similar effects of narcotics)
Anticonvulsants: describe Benzodiazepine
- Enhances the inhibitory neurotransmitter GABA, thereby depressing CNS
- Used for short period of time
- Manage acute frequent small seizures
- Adverse/side effects: sedation, respiratory depression
Anticonvulsants: how do Hydantoins and phenytoin-like drugs work? Side effects?
• Suppress Na+ influx by desensitizing Na+ channels
• Adverse/side effects: Cardiovascular changes, sedation
• Nursing considerations:
- Monitor serum drug levels
- S/sx of hydantoin toxicity?
- Phenytoin may change urine color to pink or brown
