CNS Medications and Neurotransmitters

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Questions and Answers

What should patients report when taking pramipexole?

Change in vision

New headaches

Increased appetite

New tremors or twitching (correct)

Which adverse effect is specifically associated with the combination of pramipexole and levodopa/carbidopa?

Orthostatic hypotension (correct)

Nausea

Dizziness

Weakness

What is a recommended nursing consideration for patients taking pramipexole?

Decrease fluid intake

Increase physical activity immediately

Take with meals for better absorption (correct)

Rise quickly from supine or sitting

Which mechanism do antiepileptic drugs NOT use to exert their effects?

Inhibition of dopamine receptors Signup and view all the answers

Which of the following is NOT an adverse effect associated with pramipexole?

Coughing Signup and view all the answers

What is a serious adverse effect associated with oxcarbazepine?

Hyponatremia Signup and view all the answers

What is the primary mechanism of action of oxcarbazepine?

Blocks overactive sodium channels Signup and view all the answers

What is the first step in managing status epilepticus?

Secure the airway Signup and view all the answers

Which of the following describes a notable teratogenic effect of oxcarbazepine?

Risk of serious skin reactions Signup and view all the answers

Which statement is true regarding drug monitoring for oxcarbazepine?

No drug level monitoring required Signup and view all the answers

What is the primary role of dopamine in the central nervous system?

Motor control and joy Signup and view all the answers

What class of medications are commonly used to treat Parkinson's disease?

Dopaminergic agents Signup and view all the answers

What is the primary therapeutic use of Cyclobenzaprine?

Relief of pain from acute muscle spasm Signup and view all the answers

Which drug acts directly on skeletal muscle to manage spasticity?

Dantrolene Signup and view all the answers

Which of the following medications helps to prevent the decarboxylase action in the treatment of Parkinson's?

Sinemet Signup and view all the answers

What adverse effect is common to both Baclofen and Diazepam?

Sedation Signup and view all the answers

What is a common problem associated with levodopa treatment over time?

Loss of effect after metabolism Signup and view all the answers

Which neurotransmitter is primarily implicated when there is too much acetylcholine in Parkinson's disease?

Dopamine Signup and view all the answers

Cyclobenzaprine is not effective in treating which of the following?

Spasticity Signup and view all the answers

What is a common contraindication for Cyclobenzaprine?

Concurrent use of antidepressants Signup and view all the answers

How should levodopa be administered to maximize its absorption?

On an empty stomach Signup and view all the answers

What is a significant risk associated with Dantrolene?

Hepatotoxicity Signup and view all the answers

Which of the following is an adverse effect of levodopa?

Orthostatic hypotension Signup and view all the answers

Which of the following best describes the mechanism of action of dopaminergic agents?

They directly or indirectly activate dopamine receptors Signup and view all the answers

Which of the following is an effect of spasticity?

Increased muscle tone Signup and view all the answers

What is NOT a typical treatment for muscle spasms?

Surgical intervention Signup and view all the answers

What should be avoided when taking medications that increase dopamine levels?

Medications that block dopamine receptors Signup and view all the answers

Which neurotransmitter is most associated with memory in the context provided?

Acetylcholine Signup and view all the answers

What is the primary goal of potentiation of GABA in treating epilepsy?

To decrease focal epileptic activity Signup and view all the answers

Which traditional antiepileptic drug is known for sodium channel suppression?

Phenytoin Signup and view all the answers

What is a significant risk associated with the use of traditional antiepileptic drugs?

Higher adverse effects Signup and view all the answers

Which of the following statements about phenytoin is incorrect?

It does not require metabolic monitoring. Signup and view all the answers

Which of the following side effects is commonly associated with phenytoin levels greater than 20 mcg/mL?

Cognitive impairment Signup and view all the answers

Which antiepileptic drug is known to be safer during pregnancy?

Oxcarbazepine Signup and view all the answers

What mechanism of action does valproic acid employ?

Blocks sodium and calcium channels Signup and view all the answers

Which traditional antiepileptic drug is specifically indicated for bipolar disorder and migraines?

Valproic acid Signup and view all the answers

What is the mechanism of action of cholinesterase inhibitors?

Prevents the breakdown of acetylcholine by the acetylcholinesterase enzyme Signup and view all the answers

Which of the following is a benefit of using donepezil as a cholinesterase inhibitor?

Improves quality of life and memory Signup and view all the answers

What are the common cholinergic side effects associated with cholinesterase inhibitors?

SLUDGE symptoms including salivation and urination Signup and view all the answers

What is a notable characteristic of rivastigmine as a cholinesterase inhibitor?

It is available as a transdermal patch Signup and view all the answers

What is the primary benefit of memantine as an NMDA antagonist?

It prevents neuronal calcium accumulation Signup and view all the answers

Which of the following statements is true regarding the effects of combined therapy with donepezil and memantine?

It may provide a potentiated effect Signup and view all the answers

Which cholinergic side effect could result from excessive cholinergic activity?

Diarrhea Signup and view all the answers

Which of the following accurately describes the disease-modifying effect of NMDA antagonists like memantine?

They slow the decline but do not modify the disease process Signup and view all the answers

Study Notes

Central Nervous System Medications

Medications for the central nervous system (CNS) are discussed in chapters 12 & 14.
The nervous system comprises the central nervous system (CNS), peripheral nervous system (PNS), autonomic nervous system (ANS), and somatic nervous system.
The CNS includes the brain and spinal cord.
The PNS consists of cranial nerves and spinal nerves.
The ANS controls involuntary actions like heart rate and digestion. It is further divided into parasympathetic (rest-and-digest) and sympathetic (fight-or-flight) divisions.
The somatic nervous system controls voluntary movements.

CNS Neurotransmitters

Acetylcholine is involved in memory and learning.
Dopamine is associated with pleasure and motor control.
Glutamate is essential for memory.
GABA (gamma-aminobutyric acid) plays a role in memory and movement.

Parkinson's Disease Treatments

Parkinson's Disease is characterized by too little dopamine and too much acetylcholine.
Treatments include dopaminergic agents (directly/indirectly activating dopamine receptors – more commonly used) and anticholinergic agents (blocking acetylcholine receptors).

Levodopa: Dopamine Replacement

Levodopa is a prodrug that increases dopamine levels.
Only about 2% of levodopa reaches the brain.
Food, especially high-protein meals, can delay absorption.
Levodopa has a short half-life (1-2 hours).
"Loss of effect" is a common problem as the drug metabolizes and loses effectiveness over time.

Carbidopa/Levodopa (Sinemet)

Carbidopa prevents levodopa breakdown before reaching the brain.
Allows for a lower dose of levodopa, thus reducing side effects.
Available only as a combination pill.

Levodopa Adverse Effects

Common side effects include nausea, vomiting (N/V), involuntary movements (dyskinesias), cardiovascular issues (orthostatic hypotension, dysrhythmias), and psychiatric symptoms (hallucinations, vivid dreams, paranoia).
Medications that block dopamine receptors can worsen Parkinson's symptoms.
Medications that block acetylcholine receptors can help reduce acetylcholine side effects.

Nursing Considerations for Levodopa

Patients should take levodopa without food, especially high-protein meals.
Patients should be monitored for "loss of effect".
Patients should be warned about postural changes.
Patients should report any new tremors or twitching, palpitations, racing hearts, hallucinations, or paranoia.

Pramipexole: Dopamine Receptor Agonist

Pramipexole directly activates dopamine receptors in the brain.
Often used as a first-line treatment in early stages of Parkinson's.
Can be used alone in early stages or with levodopa/carbidopa in advanced stages.

Pramipexole Adverse Effects

Common side effects include nausea, dizziness, weakness, and sleep disturbances.
Combining pramipexole with levodopa/carbidopa can lead to orthostatic hypotension, dyskinesias, or hallucinations.
Patients taking pramipexole should be monitored for sleep attacks and impulse control disorders/compulsive behaviors.

Nursing Considerations for Pramipexole

Patients should take pramipexole with meals.
Patients should be advised to rise slowly from supine or sitting positions.
Patients should report any sleep attacks or impulse control concerns.

Drugs for Seizures (AEDs)

Antiepileptic drugs (AEDs) aim to reduce neuronal activity and prevent seizure spread.
Four primary ways AEDs work:
1. Suppressing sodium influx in cell membranes.
2. Suppressing calcium influx in axon terminals.
3. Antagonizing glutamate (a neurotransmitter).
4. Potentiating GABA (a neurotransmitter).

Traditional vs Newer Anti-Epileptic Drugs

Traditional AEDs (e.g., phenytoin, phenobarbital, valproic acid) are typically less expensive and may carry more side effects and drug interactions.
Newer AEDs (e.g., oxcarbazepine) are typically more expensive and may have fewer side effects and interactions but can still have serious ones. They are often safer for pregnancy.

Phenytoin (Prototype)

Phenytoin blocks sodium channels in hyperactive neurons.
Therapeutic levels are 10-20 mcg/mL.
Highly protein-bound.
Liver metabolism can be overwhelmed by high doses.
Half-life varies with dose.
A CYP enzyme inducer.

Phenytoin Adverse Effects

Adverse effects at therapeutic levels can include mild effects like headaches or drowsiness. At higher levels (> 20 mcg/mL), more serious effects may occur including nystagmus, increased sedation, ataxia, or diplopia.
Other adverse effects include gingival hyperplasia, rashes, and teratogenic potential.
Drug interactions are common.

Valproic Acid

Blocks sodium and calcium channels and may potentiate GABA.
Used for diverse seizure types and bipolar disorder.
Common side effects include GI issues and rare but severe hepatotoxicity (liver damage).

Oxcarbazepine (Newer Prototype)

Blocks overactive sodium channels.
No drug level monitoring is required in most cases.
Serious side effects like skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), or CNS issues (dizziness, drowsiness, double vision, nystagmus, headache, ataxia) are rare but possible.
Can cause hyponatremia (low sodium levels).

Status Epilepticus

A prolonged period of continuous seizure activity.
A medical emergency.
Treatment targets securing the airway, administering intravenous (IV) or oral benzodiazepines, and following-up with antiepileptics.

Drugs for Alzheimer's Disease

Alzheimer's Disease is characterized by a lack of acetylcholine and unknown pathophysiology.
Key treatments include cholinesterase inhibitors (e.g., donepezil, rivastigmine) and N-methyl-D-aspartate (NMDA) antagonists (e.g., memantine).

Donepezil (Cholinesterase Inhibitor)

MOA: inhibits breakdown of acetylcholine.
Benefits: improved quality of life, memory, and reasoning.
Does not delay disease progression.
Available as oral disintegrating tablets (ODTs).

Rivastigmine (Cholinesterase Inhibitor)

MOA: inhibits breakdown of acetylcholine.
Benefits: improved quality of life, memory, and reasoning.
Does not delay disease progression.
Available as a transdermal patch.

Memantine (NMDA Antagonist)

MOA: blocks NMDA receptors, preventing excessive calcium accumulation.
Benefits: slows disease decline and possibly improves symptoms.
Does not modify the underlying disease process.
Generally has fewer side effects compared to other Alzheimer's medications.

Spasm and Spasticity

Spasm: involuntary muscle contraction.
Spasticity: prolonged muscle tightness.

Medications for Spasm and Spasticity

Cyclobenzaprine (centrally acting muscle relaxant) – used for spasm.
Baclofen (centrally acting muscle relaxant) – used for spasticity.
Dantrolene (direct-acting muscle relaxant) – used for spasticity.
Diazepam (benzodiazepine) used for spasticity.

Medications for Muscle Spasms

Acetaminophen
Ibuprofen
Cyclobenzaprine

Cyclobenzaprine

Therapeutic use for acute muscle spasms.
Not effective for spasticity.
Adverse effects: CNS effects (drowsiness, dizziness), and anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation).
Drug interactions include alcohol and other CNS depressants.
Tolerance and dependence can occur.

Baclofen

Acts within the spinal cord to suppress hyperactive reflexes.
Main adverse effect is sedation.
Dosing may be oral or IV for malignant hyperthermia.

Dantrolene

Acts directly on skeletal muscle.
PO dosing used for spasticity.
Serious adverse effect of hepatotoxicity.

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Description

This quiz covers essential information about medications affecting the central nervous system and their roles in various neurological functions. It includes discussions on neurotransmitters, their effects, and treatment options for conditions like Parkinson's Disease. Test your understanding of CNS components and pharmacology.