Transcript CNS Depressants and Muscle Relaxants CNS DEPRESSANTS

CNS
Depressants and Muscle
Relaxants
CNS
DEPRESSANTS
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AND
MUSCLE RELAXANTS
Discuss the action and uses of the classes of drugs used as sedatives
and hypnotics
Describe the nursing process related to patients receiving sedation
Compare and contrast the uses of barbiturates and related nursing
care
Describe the steps in caring for patients with acute depressant drug
overdose
Discuss the action and uses of direct skeletal muscle relaxants
CNS DEPRESSANTS
SLEEP
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State of unconsciousness from which a patient
can be aroused by appropriate stimulus
Needed to maintain psychiatric equilibrium and
physical well-being
Divided into two phases: REM and NREM
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REM sleep associated with dreaming
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NREM sleep divided into four stages
CNS DEPRESSANTS
SLEEP CYCLE
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Stage I
Transition from wakefulness to
sleep; 2%-5% of sleep time
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Stage II
Experienced as drifting, floating;
50% of sleep time
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Stage III
Transition from lighter to deeper
sleep
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Stage IV
Delta sleep—deep, dreamless,
restful; 10%-15% of sleep time in
healthy young adults
CNS DEPRESSANTS
REM SLEEP
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Accounts for 20% to 25% of normal sleep
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Amount of REM peaks around 5:00 AM
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Characterized by:
Rapid eye movements, increased heart rate, irregular
breathing
 Secretion of stomach acids, muscular activity, dreaming
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Important for re-establishment of psychological
equilibrium & Memory
CNS DEPRESSANTS
REM SLEEP
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The healthy young adult cycles through NREM
and REM in a 90-minute period
Stage I → Stage II → Stage III → Stage IV →
Stage III → Stage II → REM
CNS DEPRESSANTS
INSOMNIA
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Most common sleep disorder
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Experienced by 95% of adults at some time
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Usually mild and short lived
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Common causes
Lifestyle or environmental changes
 Pain, illness, anxiety
 Large amounts of caffeine; large meals before bedtime
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CNS DEPRESSANTS
INSOMNIA
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Three types of insomnia
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Initial: difficulty falling asleep
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Intermittent: difficulty staying asleep
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Terminal: waking and an inability to fall back to sleep
CNS DEPRESSANTS
SEDATIVES / HYPNOTICS
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Hypnotic—drug that produces sleep
Sedative—drug that relaxes the patient, but is not
necessarily accompanied by sleep
Actions:
Increase total sleeping time, mainly in Stages II and IV
 Decrease number of REM cycles and amount of REM sleep
 May cause REM rebound when drug
use is stopped
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CNS DEPRESSANTS
SEDATIVES / HYPNOTICS
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Actions
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Sedatives produce relaxation and rest;
hypnotics produce sleep
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Same drug may serve both functions
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Classes of sedative-hypnotics
Barbiturates
 Benzodiazepines
 Nonbarbiturate, nonbenzodiazepines
 Miscellaneous agents
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CNS DEPRESSANTS
SEDATIVES / HYPNOTICS
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Uses
Temporary treatment of insomnia
 Decrease anxiety and increase relaxation and/or
sleep before diagnostic or operative procedures
 Anticonvulsive agents
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CNS DEPRESSANTS
NURSING PROCESS
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Take baseline assessments
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Note sleep disruption patterns
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Determine activities done just before bed
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Ask about patient stressors
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Identify caffeine sources in dietary history
CNS DEPRESSANTS
NURSING PROCESS
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Before administering a sedative-hypnotic,
determine the actual need for it
Patients with history of sleep apnea or
respiratory difficulties -higher risk for
respiratory depression
Older adults may react paradoxically
CNS DEPRESSANTS
NURSING PROCESS
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Encourage standard bedtime
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Avoid late, heavy meals
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Limit caffeine and alcohol intake
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Control sleep environment
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Promote stress-reducing techniques
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Discuss benefits of medication compliance and nonpharmacologic
interventions
Encourage patient use of self-assessment form
CNS DEPRESSANTS
NURSING PROCESS
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Perform ongoing monitoring for therapeutic and
adverse effects
There should be written standards that specify
minimum monitoring criteria for providing safe
care
Always follow the policies and procedures of the
organization and document the monitored
findings
CNS DEPRESSANTS
BARBITURATES
First introduced in 1903
 Mainstay of therapy until 1960
 Use has declined in favor of benzodiazepines
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Common barbiturates:
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butabarbital (Butisol)
pentobarbital (Nembutol)
phenobarbital (Luminal)
secobarbital (Seconal)
CNS DEPRESSANTS
BARBITURATES
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Actions
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Reversibly depress excitable tissues
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Effect depends on dose, tolerance, route of
administration, patient’s condition
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Suppress REM and Stage III/IV sleep patterns
when used for hypnosis
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Long half-lives; residual sedation common
CNS DEPRESSANTS
BARBITURATES
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Uses
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Anticonvulsant
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General anesthetic (ultrashort acting)
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Sedation before a diagnostic procedure (short acting)
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Sedative and hypnotic effect (rare use)
CNS DEPRESSANTS
BARBITURATES
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Baseline assessment should include
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Respiratory rate and depth
Level of consciousness
State of arousal
Behavior
Motor function
Side effects to report
Habitual use—can result in physical dependence
 Hypersensitivity—infrequent; hives, rash, pruritus
 Blood dyscrasias—rare; schedule routine lab studies
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CNS DEPRESSANTS
BARBITURATES
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Patient Education: Side effects to expect
Morning “hangover”
 Blurred vision
 Transient hypotension on arising
 Impaired coordination
 Lethargy
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Drug interactions
Alcohol, antihistamines, tranquilizers, and analgesics
increase effects of barbiturates
 Patients taking phenytoin and barbiturates for
seizure control should have drug levels monitored to
ensure adequate dosages
 Reduced effectiveness of other medicines
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CNS DEPRESSANTS
BENZODIAZEPINES
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Wide safety margin
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More than 200 derivatives
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Difficult to describe as a class, but include:
Anticonvulsants
 Antianxiety agents
 Sedative-hypnotic agents
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Hypnotic Drugs:
 Long acting
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estazolam (Prosom), flurazepam (Dalmane), others
Short acting
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temazepam (Restoril),triazolam (Halcion)
CNS DEPRESSANTS
BENZODIAZEPINES
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Actions
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Act on specific CNS sites
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Decrease Stage III/IV sleep and to a lesser extent, REM
Uses
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E.g., sedative-hypnotics affect type 1 and type 2 GABA receptors; bind to the
receptors to stimulate the release of GABA
Most commonly used sedative-hypnotics
Preoperative sedative
Conscious sedation
Agitation
Depression
Balanced anesthesia
Therapeutic outcomes
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To produce mild sedation
For short-term use to produce sleep
Preoperative sedation with amnesia
CNS DEPRESSANTS
NURSING PROCESS
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Assessment
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Vital signs, especially blood pressure, should be assessed while the patient is sitting and lying
down before administering benzodiazepines
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Give15 to 30 minutes before bedtime for maximum effectiveness in inducing sleep
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Most benzodiazepines cause REM rebound and a tired feeling the next day;
use with caution in the elderly
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Check liver function tests
Side effects to report
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Physical dependence can result from chronic use
Blood dyscrasias; hepatotoxicity
Patient Education
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Side effects to expect: Morning “hangover,” blurred vision, transient hypotension on arising
Toxic effects - increased if used with alcohol, tranquilizers, antihistamines, analgesics, and
anesthetics
Smoking increases the metabolism of benzodiazepines
CNS DEPRESSANTS
NON-BARBITURATES
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/ NON-BENZODIAZEPINES
All cause CNS depression, but mechanisms of action differ
zalepion (Sonata), zolpidem (Ambien), and eszoplicone (Lunesta)
Share many characteristics of benzodiazepines
 Used to treat insomnia
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Actions
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Uses
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Variable effects on REM sleep
Tolerance development
Rebound REM sleep
Insomnia after discontinuation
Sedative and hypnotic effects
Therapeutic outcomes
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To produce mild sedation
For short-term use to produce sleep
CNS DEPRESSANTS
NON-BARBITURATES/NON-BENZODIAZEPINES
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Nursing Process:
Vital signs, especially blood pressure, should be assessed
while the patient is sitting and lying down before
administering
 Laboratory results should be monitored for hepatic
dysfunction or blood abnormalities
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Patient Education:
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Side effects to expect:
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Morning “hangover”
Blurred vision
Transient hypotension on arising
Restlessness, anxiety
CNS MUSCLE RELAXANTS
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Relieves pain associated with skeletal muscle spasms
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Majority are central acting
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Direct acting
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CNS is the site of action
Similar in structure and action to other CNS depressants
Acts directly on skeletal muscle
Closely resembles GABA
Relief of painful musculoskeletal conditions
Muscle spasms
 Management of spasticity of severe chronic disorders
 Multiple sclerosis, cerebral palsy
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Work best when used along with physical therapy
CNS MUSCLE RELAXANTS
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Adverse Effects
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Usually seen in 0.2% of patients treated for more
than 60 days – to be used only for short term
Extension of effects on CNS and skeletal muscles
 Euphoria
 Lightheadedness
 Dizziness
 Drowsiness
 Fatigue
 Muscle weakness, others
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Toxicity
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Overdose involves CNS – airway, IV fluids, cardiac
monitor
CNS MUSCLE RELAXANTS
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dantrolene (Dantrium)
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Works directly on skeletal muscle
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Uses: Malignant hyperthermia crisis & Spasticity
CNS MUSCLE RELAXANTS
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baclofen (Lioresal)
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cyclobenzaprine (Flexeril)
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dantrolene (Dantrium)
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metaxalone (Skelaxin)
CNS MUSCLE RELAXANTS
NURSING PROCESS
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Patient Assessment
Determine allergies, mental status,
 Sleep diary & review sleep habits
 Renal and hepatic function testing
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Patient Education
Intended for short term use
 Same precautions as with benzodiazepines
 Avoid alcohol and benzodiazepines
 Caution to avoid overdose
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CNS
DEPRESSANTS & MUSCLE RELAXANTS
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As individuals age, their sleep becomes:
a. more fragmented.
 b. more sound.
 c. characterized by fewer nocturnal awakenings
 d. both 2 and 3
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CNS
DEPRESSANTS AND MUSCLE RELAXANTS
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Long term administration of benzodiazepines
may result in:
a. nephrotoxicity.
 b. withdrawal symptoms if withdrawn rapidly.
 c. a rush of morning energy with repeated
usage.
 d. seizures during the time it is being
administered.
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CNS
DEPRESSANTS & MUSCLE RELAXANTS
1. Benzodiazepines work by ________________. An example of a
benzodiazepine is _______________.
2. Restoril is used as a ________________________ and has the adverse
effects of ___________.
3. Larger dosages of sedative-hypnotics result in a _____________ effect.
Smaller doses have a _______________ effect.
4. Phenobarbital is a(n) ____________________ drug.
5. Zolpidem is classified as a(n) _______________drug.
6. The only skeletal muscle relaxant that acts directly on skeletal
muscle is __________.