Medications That Affect the Nervous System

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Medications That Affect the Nervous System

• Unit 29

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Objectives

• Describe the nervous system
• Define pain
• Explain various techniques for assessing pain in
  a child
• State the schedule, duration, usual sedative
  dose, and usual hypnotic dose of selected
  barbituates
• Identify selected anesthetic drugs

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Nervous System

• Consists of the brain and spinal cord (CNS) and
  network of nerves and tissues throughout the body
  (PNS)
• PNS connects to the brain and spinal cord through
  a series of 12 pair of cranial nerves and 31 pair
  of spinal nerves
• Our senses of hearing, taste, equilibrium, touch,
  smell, sight all rely on nerves to function
  properly

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Pain

• Sensory and emotional experience associated with
  actual or potential tissue damage
• Measured by threshold and intensity
• Pain threshold level of stimulus that results in
  the perception of pain
• Pain intensity degree of pain felt by the
  individual

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Methods for Pain Relief

• Behavior modification-biofeedback, hypnosis
• Electrostimulation-using electrodes
• Acupuncture
• Exercise
• Ice
• Surgery
• Heat-after swelling has subsided

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Assessment of Pain

• Pain is subjective-the patient needs to describe
  the location, intensity, onset, duration, sources
  of relief, and sources of distress.
• 1. History of the pain
• 2. Physical signs and symptoms
• 3. Facial expressions
• 4. Body movements

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Effectiveness of Treatment

• Two methods that are frequently used include
  rating scales and questionnaires
• 1. McGill-Melzack Pain Questionnaire
• 2. Wong-Baker Face Rating Scale shows five faces
  with the numbers 0-5 beneath the picture 0no
  pain and 5most intense pain

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Analgesics

• Used to relieve pain caused by disease or other
  conditions without causing the patient to lose
  consciousness
• Ex. Morphine (opiates)
• Classified as narcotics because they are known to
  cause dependency and tolerance

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Narcotic Analgesics

• Inhibit ascending pain pathways in the central
  nervous system (CNS)
• Uses relief of moderate to severe pain
• Contraindications do not give to patient with
  any drug addictions
• Can cause drug dependence and have the potential
  for being abused
• Warnings respiratory depression

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Narcan

• Narcotic antagonist that prevents or reverses the
  effects of opiods including respiratory
  depression, sedation, and hypotension
• Given in cases of drug overdose

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Analgesic-Antipyretics

• Combination medications that act to both relieve
  pain (analgesic) and reduce fever (antipyretic)
• Examples include Tylenol, Bayer, and Naproxen

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Sedatives and Hypnotics

• Depress the CNS by interfering with the
  transmission of nerve impulses
• Sedatives produce a calming effect without
  causing sleep
• Hypnotic sufficient to cause sleep

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Barbituates

• Action affects the entire CNS
• Large doses depress the respiratory centers in
  the medulla and can lead to respiratory arrest
  and death
• Continued use over time diminishes their
  effectiveness
• Tolerance can develop very rapidly, as soon as
  one week after first dose

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Barbituates

• Depress the sensory cortex, decrease motor
  activity, alter cerebral function, and produce
  drowsiness
• Depressed activity in the brain interferes with
  the transmission of impulses to the cerebral
  cortex
• Uses insomnia, sedation

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Benzodiazepines

• Use in relief of anxiety
• Effect has a duration between 6-8 hours
• Medication should be limited to a period of 7-10
  days
• Have an additional sedative effect when taken
  with other CNS depressants including alcohol,
  antihistamines, antidepressants, and other opiods

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Antiparkinsonian Drugs

• Parkinsons disease is a neurologic disorder
  characterized by the development of a fine
  tremor, muscle weakness and rigidity, and decline
  in posture and equilibrium
• Associated with an imbalance of the
  neurotransmitters acetylcholine and dopamine in
  the brain

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Antiparkinsonian Drugs

• Used in treating symptoms including
  bradykinesia, tremor, and equilibrium
• Therapy attempts to replenish dopamine levels and
  inhibit the effects of acetlycholine in the brain
• Prolong the action of dopamine by blocking its
  uptake into presynaptic neurons in the CNS

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Alzheimers Disease

• Progressive degeneration of brain tissue that
  usually begins after age 60 however it can
  strike people as young as 30
• Characterized by decrease in mental functioning
  including memory, comprehension, and speech
• Physical symptoms may include odd gait, loss of
  coordination, mood swings

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Alzheimers Disease

• Paths of communication between brain cells become
  distorted by deposits of a protein called
  amyloid.
• In addition, levels of acetylcholine drop causing
  more cell-to-cell communication problems
• Brain cells shrivel and die, causing certain
  areas of the brain to shrink

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Alzheimers Disease

• Average length of duration from onset to death is
  10 years
• Fourth leading cause of death
• Age and family history are the two most important
  risk factors for developing this disease
• Alzheimers is incurable
• Treatment Aricept

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Anticonvulsants

• Epilepsy is the most common of the seizure
  disorders and affects 1 of the population
• Epilepsy is characterized by recurrent abnormal
  electrical misfirings in the brain
• Causes can be either idiopathic or symptomatic
• Causes brain lesions, metabolic disease

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Categories of Seizures

• 1. Partial seizures (focal seizures) electrical
  disturbance is localized to areas of the brain
  near the source of the seizure
• 2. Generalized seizures (bilateral seizures)
  without local onset that involve both hemispheres
  of the brain

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Categories of Seizures

• 3. Unilateral seizures electrical misfiring is
  confined to one of the two hemispheres of the
  brain
• 4. Unclassified epileptic seizures cannot be
  placed into one of the other three categories
  because of incomplete data
• Therapy aims to obtain the greatest degree of
  control without undesirable side effects

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Anesthetics

• Drugs that interfere with the conduction of nerve
  impulses and are used to produce loss of
  sensation, muscle relaxation, and loss of
  consciousness
• Local block nerve transmission in the area where
  they are applied
• General affect the entire CNS and cause partial
  or complete loss of consciousness

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Ophthalmic Drugs

• Used in the treatment of glaucoma, during
  diagnostic examination of the eye, and during
  intraocular surgery
• Glaucoma eye disease characterized by increased
  intraocular pressure, which if left untreated,
  causes atrophy of the optic nerve and possible
  blindness
• Causes imbalance of aqueous humor

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Vertigo

• Term used to describe the illusion of movement
• Causes a disturbance in equilibrium where the
  patient experiences dizziness, lightheadedness,
  and N/V