chapter 12 central nervous system depressants and muscle relaxants l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
CHAPTER 12 Central Nervous System Depressants and Muscle Relaxants PowerPoint Presentation
Download Presentation
CHAPTER 12 Central Nervous System Depressants and Muscle Relaxants

Loading in 2 Seconds...

play fullscreen
1 / 40

CHAPTER 12 Central Nervous System Depressants and Muscle Relaxants - PowerPoint PPT Presentation


  • 179 Views
  • Uploaded on

CHAPTER 12 Central Nervous System Depressants and Muscle Relaxants . CNS Depressants . Sedatives or Hypnotics. CNS Depressants . Sedatives Drugs that have an inhibitory effect on the CNS to the degree that they reduce: Nervousness Excitability Irritability without causing sleep.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'CHAPTER 12 Central Nervous System Depressants and Muscle Relaxants' - ostinmannual


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 12 central nervous system depressants and muscle relaxants

CHAPTER 12Central Nervous System Depressants and Muscle Relaxants

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants
CNS Depressants

Sedatives or Hypnotics

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants3
CNS Depressants

Sedatives

  • Drugs that have an inhibitory effect on the CNS to the degree that they reduce:
    • Nervousness
    • Excitability
    • Irritability without causing sleep

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants cont d
CNS Depressants (cont'd)

Hypnotics

  • Calm or soothe the CNS to the point that they cause sleep
  • A sedative can become a hypnotic if it is given in large enough doses

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants cont d5
CNS Depressants (cont'd)

Sedative-hypnotics—dose dependent

  • At low doses, calm or soothe the CNS without inducing sleep
  • At high doses, calm or soothe the CNS to the point of causing sleep

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

sleep
Sleep
  • Normal sleep is cyclic and repetitive
  • A sleeping person is unaware of sensory stimuli within the immediate environment
  • Rapid eye movement (REM)
  • Non–rapid eye movement (non-REM)
  • Sleep stages

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

table 12 2 stages of sleep
Table 12-2 Stages of Sleep

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

sedative hypnotics barbiturates
Sedative-Hypnotics: Barbiturates
  • First introduced in 1903; standard agents for insomnia and sedation
  • Habit forming
  • Only a handful commonly used today due in part to the safety and efficacy of benzodiazepines

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates four categories
Barbiturates: Four Categories
  • Ultrashort
    • mephobexital, thiamylal, thiopental
  • Short
    • pentobarbital, secobarbital
  • Intermediate
    • butabarbital
  • Long
    • phenobarbital, mephobarbital

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

therapeutic index
Therapeutic Index
  • Dosage range within which the drug is effective but above which is rapidly toxic
  • Barbiturates have a very narrow therapeutic index

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

table 12 3 barbiturates onset and duration
Table 12-3 Barbiturates: Onset and Duration

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates mechanism of action
Barbiturates: Mechanism of Action

• Site of action

    • Brainstem (reticular formation)
  • By inhibiting GABA, nerve impulses traveling in the cerebral cortex are also inhibited

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates drug effects
Barbiturates: Drug Effects

• Low doses: sedative effects

  • High doses: hypnotic effects (also lowers respiratory rate)
  • Notorious enzyme inducers
    • Stimulate liver enzymes that cause the metabolism or breakdown of many drugs

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates indications
Barbiturates: Indications

• Hypnotic

  • Sedative
  • Anticonvulsant
  • Anesthesia for surgical procedures

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates side effects
Barbiturates: Side Effects

Body SystemEffects

CNS Drowsiness, lethargy, vertigo, mental depression, coma

Respiratory Respiratory depression, apnea, bronchospasms, cough

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates side effects cont d
Barbiturates: Side Effects (cont'd)

Body SystemEffects

GI Nausea, vomiting, diarrhea constipation

Other Agranulocytosis, vasodilation, hypotension, Stevens-Johnson syndrome

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates side effects cont d17
Barbiturates: Side Effects (cont'd)
  • Reduce REM sleep, resulting in:
    • Agitation
    • Inability to deal with normal stress

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates toxicity and overdose
Barbiturates:Toxicity and Overdose
  • Overdose frequently leads to respiratory depression, and subsequently, respiratory arrest
  • Overdose produces CNS depression (sleep to coma and death)
  • Can be therapeutic
    • Anesthesia induction
    • Uncontrollable seizures: “phenobarbital coma”

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

barbiturates drug interactions
Barbiturates:Drug Interactions
  • Additive effects
    • ETOH, antihistamines, benzodiazepines, narcotics, tranquilizers
  • Inhibited metabolism
    • MAOIs will prolong effects of barbiturates
  • Increased metabolism
    • Reduces anticoagulant response, leading to possible clot formation

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

common barbiturates
Common Barbiturates
  • butabarbital (Butisol)
  • pentobarbital (Nembutol)
  • phenobarbital (Luminal)
  • secobarbital (Seconal)

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants benzodiazepines
CNS Depressants: Benzodiazepines

Most frequently prescribed sedative-hypnotics

  • Most commonly prescribed drug classes
  • Favorable side effect profiles
  • Efficacy
  • Safety

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines classification
Benzodiazepines: Classification
  • Classified as either:
    • Sedative-hypnotic
    • anxiolytic (medication that relieves anxiety)

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines sedative hypnotic types
Benzodiazepines:Sedative-Hypnotic Types
  • Long acting
    • estazolam (Prosom), quazepam (Doral)
  • Short acting
    • flurazepam (Dalmane), temazepam (Restoril)
    • triazolam (Halcion)

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants nonbenzodiazepine hypnotics
CNS Depressants: Nonbenzodiazepine Hypnotics

Zalepion (Sonata) and zolpidem (Ambien)

  • Share many characteristics of benzodiazepines

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines mechanism of action
Benzodiazepines:Mechanism of Action
  • Depress CNS activity
  • Affect hypothalamic, thalamic, and limbic systems of the brain
  • Benzodiazepine receptors
  • Do not suppress REM sleep as much as barbiturates do
  • Do not increase metabolism of other drugs

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines drug effects
Benzodiazepines:Drug Effects
  • Calming effect on the CNS
  • Useful in controlling agitation and anxiety
  • Reduce excessive sensory stimulation, inducing sleep
  • Induce skeletal muscle relaxation

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines indications
Benzodiazepines:Indications
  • Sedation
  • Sleep induction
  • Skeletal muscle relaxation
  • Anxiety relief
  • Treatment of alcohol withdrawal

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines indications cont d
Benzodiazepines:Indications (cont'd)
  • Agitation
  • Depression
  • Epilepsy
  • Balanced anesthesia

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

benzodiazepines side effects
Benzodiazepines: Side Effects

Mild and infrequent

  • Headache
  • Drowsiness
  • Dizziness
  • Vertigo
  • Lethargy
  • Paradoxical excitement (nervousness)
  • “Hangover effect”

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

cns depressants nursing implications
CNS Depressants: Nursing Implications
  • Before beginning therapy, perform a thorough history regarding allergies, use of other medications, health history, and medical history
  • Obtain baseline vital signs and I&O, including supine and erect BPs
  • Assess for potential disorders or conditions that may be contraindications, and for potential drug interactions

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

nursing implications
Nursing Implications
  • Give 15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep
  • Most benzodiazepines (except flurazepam) cause REM rebound and a tired feeling the next day; use with caution in the elderly
  • Patients should be instructed to avoid alcohol and other CNS depressants

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

nursing implications32
Nursing Implications
  • Check with physician before taking any other medications, including OTC medications
  • It may take 2 to 3 weeks to notice improved sleep when taking barbiturates
  • Rebound insomnia may occur for a few nights after a 3- to 4-week regimen has been discontinued

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

nursing implications33
Nursing Implications
  • Safety is important
    • Keep side rails up or use bed alarms
    • Do not permit smoking
    • Assist patient with ambulation (especially the elderly)
    • Keep call light within reach
  • Monitor for side effects

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

nursing implications34
Nursing Implications
  • Monitor for therapeutic effects
    • Increased ability to sleep at night
    • Fewer awakenings
    • Shorter sleep-induction time
    • Few side effects, such as hangover effects
    • Improved sense of well-being because of improved sleep

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

muscle relaxants
Muscle Relaxants
  • Act to relieve pain associated with skeletal muscle spasms
  • Majority are central acting
    • CNS is the site of action
    • Similar in structure and action to other CNS depressants
  • Direct acting
    • Acts directly on skeletal muscle
    • Closely resembles GABA

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

muscle relaxants indications
Muscle Relaxants: Indications
  • Relief of painful musculoskeletal conditions
    • Muscle spasms
    • Management of spasticity of severe chronic disorders
    • Multiple sclerosis, cerebral palsy
  • Work best when used along with physical therapy

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

muscle relaxants indications cont d
Muscle Relaxants: Indications (cont'd)
  • dantrolene
    • Malignant hyperthermia crisis

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

muscle relaxants side effects
Muscle Relaxants: Side Effects
  • Extension of effects on CNS and skeletal muscles
    • Euphoria
    • Lightheadedness
    • Dizziness
    • Drowsiness
    • Fatigue
    • Muscle weakness

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

common muscle relaxants
Common Muscle Relaxants
  • baclofen (Lioresal)
  • cyclobenzaprine (Flexeril)
  • dantrolene (Dantrium)
  • metaxalone (Skelaxin)
  • tizanidine (Zanaflex)

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

muscle relaxants nursing implications
Muscle Relaxants: Nursing Implications
  • See others listed for CNS depressants

Mosby items and derived items © 2005, 2002 by Mosby, Inc.