Untitled Quiz

Drugs Affecting the Central Nervous System

• Covering a wide range of drugs affecting the CNS and PNS
• Includes various classifications of drugs, indications, actions, and examples

The Nervous System

• Central Nervous System (CNS): The body's master control unit
  • Spinal cord connects brain to peripheral nervous system
  • Brain stem connects the spinal cord to other brain parts
  • Divided into hindbrain, midbrain, forebrain.
• Peripheral Nervous System (PNS): Body's link to the outside world
  • Autonomic Nervous System (ANS): involuntary processes
    • Adrenergic (sympathetic): Prepares body for action/stress (fight or flight)
    • Cholinergic (parasympathetic): Calms body to conserve energy (rest and digest)
  • Somatic Nervous System (SNS): Voluntary movements
    • Carries sensory information from sensory organs to CNS
    • Relays motor (movement) commands to muscles

Brain

• Cerebrum: Largest part of the brain
• Cerebellum: Coordinates movement
• Brain stem: Breathing, body temperature, digestion, alertness, and swallowing.
  • Midbrain, Pons, Medulla Oblongata.
    • Connects spinal cord with higher brain and other brain parts
• Meninges: Membranes protecting the brain and spinal cord
• Ventricles of the Brain (fluid filled spaces)
  • Choroid Plexus produces cerebrospinal fluid (CSF)
  • CSF flows through ventricles and into the subarachnoid space
• Cerebral Spinal Fluid (CSF):
  • Produced by Choroid Plexus inside the Brain ventricles.
• Limbic System: Emotions and memories (Hypothalamus, Amygdala, Hippocampus).
  • Amygdala: involved in aggression, fear & flight
  • Hypothalamus: hunger, thirst and body temperature regulation
  • Hippocampus: process memories

Brain Stem

• Thalamus
• Pons
• Midbrain
• Medulla Oblongata
• Cranial nerves

Neuron Cell

• Dendrites: Branch-like projections receiving information from other neurons
• Cell body: Contains the nucleus, cytoplasm
• Axon: Elongated part carrying information from a nerve to effector cells
• Axon terminal: Site of transmission to effector cells
• Schwann cell: Produces myelin
• Myelin: Insulates axon, increasing transmission speed of an action potential
• Nodes of Ranvier: Gaps in the myelin sheath
• Efferent fibers: EXIT CNS.
• Afferent fibers: ENTRY into CNS.

Neuron Cell Types

• Bipolar: Interneuron
• Unipolar: Sensory neuron
• Multipolar: Motor neuron
• Pyramidal cell

Myelin Sheath Formation

• Schwann cells form myelin sheath surrounding axons.

Nerve Synapse

• Synaptic cleft: Space between two neurons
• Vesicles: Contain neurotransmitters
• Sending/Receiving neuron: Transmit/receive neurotransmitters.

Nervous System Drugs Classifications (CNS)

• Neurological and neuromuscular agents
• CNS depressants
• Anticonvulsants
• Drugs for neurological disorders
• Drugs for neuromuscular disorders
• Antipsychotic and anxiolytic
• Antidepressants and mood stabilizers
• Adrenergic and cholinergic drugs
• Adrenergic and cholinergic blockers

Nervous System Drugs Classifications (Peripheral Nervous System)

Critical Thinking

• 4 part process to analyze a given drug
• Assess the condition & what part of nervous system is affected
• Understanding how the drug works on the affected party
• Know what the nurse must perform to ensure drug is used correctly

Case Scenarios

• Provide 15 case scenarios that relate to different neurological conditions.
  • Includes names of drugs that are indicated for each condition.

CNS Drug Classifications

• Anxiolytic and hypnotic agents
• Antidepressant Agents
• Psychotherapeutic agents
• Antiepileptic agents
• Antiparkinsonism agents
• Muscle relaxants
• Narcotics and anti-migraine drugs
• General and local anesthetics
• Neuromuscular blocking agents

Anti-Parkinsonism

• Anticholinergics: Block acetylcholine to help balance the acetylcholine/dopamine imbalance
• Dopaminergics: Increase dopamine at receptor sites, restoring the balance.

Muscle Relaxants

• Centrally acting, and Direct-acting
• Interfere with calcium release in muscle fibers, therefore preventing muscle contraction.

Narcotics

• Narcotic Agonists
• Narcotic agonist/antagonist
• Narcotic antagonists
• Act at opioid receptors in CNS.
• Relief of pain, analgesia.

Anti-Migraine Drugs

• Ergot derivatives
• Triptans
• Agonists, and receptor binding to stop and prevent migraines

Anesthetic Drugs

• General: Depress RAS and cerebral cortex
• Local: Interrupts nerve impulses. Prevents sodium entry

Neuromuscular Blocking Agents

• Non-depolarizing vs depolarizing agents

Adrenergic Drugs

• Beta vs Alpha Drugs, agonists vs blockers
• Increase in heart rate & myocaridial contractility
• Increased in blood pressure.
• Causes changes in blood vessels
  • Causes changes to organs.
  • Uses: shock, bronchospasm, hypersensitivity

Cholinergic Drugs

• Direct vs indirect action of agonists vs blockers
• Mimics the effects of ACh in the PNS
• Causes: Slowed heart rate, decrease myocardial infarction

Anti-Cholinergic Agents

• Block acetylcholine receptors in the CNS
  • Causes: increase in heart rate, dilation of pupils, decreases secretions.

What are the Nursing Interventions in Giving These Drugs?

• 7 part process to use drugs correctly
  • Make a drug study
  • Assess before giving drug; indications, contraindications.
  • Properly prepare patient; cultural/age/environmental considerations.
  • Monitor side effects/adverse effects
  • Know when to refer to doctor.
  • Know how to handle side effects