CNS Depressants and Sleep Mechanisms

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Questions and Answers

Which statement best describes Ramelteon?

It is classified as a controlled substance.

It primarily addresses sleep maintenance issues.

It acts as an agonist at melatonin receptors. (correct)

It is a CNS depressant.

What is a notable concern associated with Zolpidem (Ambien)?

It has a long duration of action without any variants.

It causes excessive daytime sleepiness.

It is linked with somnambulation. (correct)

It is classified as a controlled substance.

Why are barbiturates used less frequently today?

Benzodiazepines offer better safety and efficacy. (correct)

They are non-habit forming.

They have a higher therapeutic index than benzodiazepines.

They have a longer duration of action than benzodiazepines.

What does a low therapeutic index for barbiturates indicate?

The effective and toxic dosages are closely related. Signup and view all the answers

How do barbiturates primarily exert their effects?

By potentiating GABA action. Signup and view all the answers

Which barbiturate class is most appropriate for controlling convulsions during a surgical procedure?

Ultrashort acting Signup and view all the answers

Which of the following is NOT a contraindication for the use of barbiturates?

Mild respiratory difficulty Signup and view all the answers

What is a potential hematologic adverse effect of barbiturates?

Thrombocytopenia Signup and view all the answers

What impact do barbiturates have on REM sleep?

Reduction in REM sleep Signup and view all the answers

A patient experiencing respiratory depression after a barbiturate overdose is likely experiencing which of the following?

CNS depression Signup and view all the answers

In which scenario might an older adult patient require caution when administered barbiturates?

Increased liver function tests Signup and view all the answers

Which of the following is a common adverse effect of barbiturates on the cardiovascular system?

Vasodilation Signup and view all the answers

What is considered an indication for using long-acting barbiturates?

Epileptic seizure prophylaxis Signup and view all the answers

What is the primary mechanism of action for muscle relaxants?

Act directly on skeletal muscle by resembling GABA Signup and view all the answers

Which condition is dantrolene specifically indicated for?

Malignant hyperthermia Signup and view all the answers

What is a common adverse effect of muscle relaxants?

Euphoria Signup and view all the answers

In the case of muscle relaxant overdose, what is the primary method of treatment?

Conservative supportive measures Signup and view all the answers

Which of the following muscle relaxants is known to primarily cause sedation?

Cyclobenzaprine (Flexeril) Signup and view all the answers

What should patients taking muscle relaxants be cautioned against?

Interactions with other CNS depressants Signup and view all the answers

What distinguishes hypnotics from sedatives?

Hypnotics have a much more potent effect on the CNS than sedatives. Signup and view all the answers

Which muscle relaxant is commonly used for multiple sclerosis and other chronic disorders?

Baclofen (Lioresal) Signup and view all the answers

Which adverse effect is most likely experienced by patients on muscle relaxants?

Dizziness Signup and view all the answers

Which group of CNS depressants is least likely to suppress REM sleep?

Benzodiazepines Signup and view all the answers

What effect do benzodiazepines have on sensory stimulation?

They reduce excessive sensory stimulation. Signup and view all the answers

Which of the following is NOT a common indication for benzodiazepine use?

Acute respiratory distress Signup and view all the answers

Which of the following adverse effects is commonly associated with benzodiazepines?

Cognitive impairment Signup and view all the answers

Which contraindication applies specifically to the use of benzodiazepines?

Narrow-angle glaucoma Signup and view all the answers

What is a primary therapeutic use of benzodiazepines in the context of acute seizure disorders?

To depress CNS activity Signup and view all the answers

What is a common outcome of using benzodiazepines in older adults?

Fall hazard due to sedation Signup and view all the answers

Which mechanism underlies the action of benzodiazepines on the CNS?

Depressing CNS activity via GABA receptors Signup and view all the answers

For which condition might benzodiazepines NOT be prescribed?

Long-term depression management Signup and view all the answers

What is the primary use of baclofen?

To treat chronic spastic muscular conditions Signup and view all the answers

Which statement about cyclobenzaprine is true?

It can cause significant sedation. Signup and view all the answers

What should be monitored before starting therapy with muscle relaxants?

Baseline vital signs and medication interactions Signup and view all the answers

What is a recommended timing for administering hypnotics for maximum effectiveness?

30 to 60 minutes before bedtime Signup and view all the answers

Rebound insomnia may occur after discontinuing which duration of a hypnotic regimen?

3 to 4 weeks Signup and view all the answers

What is the primary concern for older adults when using benzodiazepines?

They may experience REM rebound and tiredness the next day. Signup and view all the answers

Which of the following is NOT a therapeutic effect to monitor for with muscle relaxants?

Increased alertness during the day Signup and view all the answers

Which safety precaution should be taken for patients using CNS depressants?

Using bed alarms or raising side rails. Signup and view all the answers

Study Notes

Central Nervous System Depressants

CNS Depressants are drugs that inhibit nervousness, excitability, and irritability.
Sedatives reduce CNS activity, while Hypnotics cause sleep.
Sedative-hypnotics are dose-dependent, acting as sedatives at low doses and hypnotics at higher doses.
Barbiturates, benzodiazepines, and miscellaneous drugs are the three main groups of sedative-hypnotics.

Sleep

Sleep is a transient, reversible, and periodic state of rest marked by decreased physical activity and consciousness.
It is cyclic and repetitive, with the sleeper unaware of sensory stimuli.
Sleep architecture includes Rapid Eye Movement (REM) sleep and Non-REM sleep.
REM interference and REM rebound are possible consequences of certain medications.

Benzodiazepines

Benzodiazepines are classified as either sedative-hypnotics or anxiolytics.
They depress CNS activity, affecting the hypothalamus, thalamus, and limbic systems.
Benzodiazepine receptors are linked to Gamma-aminobutyric acid (GABA).
They do not suppress REM sleep as much as barbiturates and don't increase the metabolism of other drugs.

Benzodiazepine Effects and Indications

Effects: Calming, reduce anxiety, induce sleep, relax skeletal muscles.
Indications: Sedation, sleep induction, muscle relaxation, anxiety relief, anxiety-related depression, treatment of seizures and alcohol withdrawal, agitation relief, balanced anesthesia, moderate sedation.

Benzodiazepine Contraindications and Adverse Effects

Contraindications: Drug allergy, narrow-angle glaucoma, pregnancy.
Adverse Effects: Headache, drowsiness, dizziness, cognitive impairment, vertigo, lethargy, fall hazard in older adults, “hangover” effect or daytime sleepiness.

Nonbenzodiazepine Hypnotics

Ramelteon (Rozerem) is structurally similar to melatonin and works as an agonist at melatonin receptors in the CNS.
Zolpidem (Ambien) is a short-acting nonbenzodiazepine hypnotic with a lower incidence of daytime sleepiness.

Barbiturates

Introduced in 1903, they were initially the standard drugs for insomnia and sedation but are now less commonly used due to their habit-forming nature and low therapeutic index.

Barbiturate Action and Indications

Mechanism of action: Potentiation of GABA action in the brainstem, inhibiting nerve impulses in the cerebral cortex.
Indications: Anesthesia for short surgical procedures, anesthesia induction, control of convulsions, reduction of intracranial pressure in neurologic patients, sedation and control of convulsive conditions, epileptic seizure prophylaxis.

Barbiturate Contraindications and Adverse Effects

Contraindications: Drug allergy, pregnancy, significant respiratory difficulties, severe kidney or liver disease, caution in older adults.
Adverse Effects: Cardiovascular (vasodilation & hypertension), CNS (drowsiness, lethargy, vertigo), respiratory (depression & cough), GI (nausea, vomiting, diarrhea, constipation), hematologic (agranulocytosis & thrombocytopenia), hypersensitivity reactions, Stevens-Johnson syndrome, reduced REM sleep, agitation.

Muscle Relaxants

Used to relieve painful musculoskeletal conditions (muscle spasms), manage spasticity in chronic disorders (multiple sclerosis, cerebral palsy), and treat malignant hyperthermia.
They work best in conjunction with physical therapy.

Muscle Relaxant Adverse Effects

Adverse Effects: Euphoria, lightheadedness, dizziness, drowsiness, fatigue, muscle weakness.

Muscle Relaxant Toxicity and Management

Toxicity primarily involves the CNS, with no specific antidote or reversal.
Management: Conservative supportive measures. Adequate airway maintenance, EKG monitoring, fluid administration to prevent crystalluria if taken with other CNS depressants.

Common Muscle Relaxants

Baclofen (Lioresal) is available in oral and injectable forms, with an implantable baclofen pump device.
Cyclobenzaprine (Flexeril) is a centrally acting muscle relaxer and the most commonly used, but it can cause significant sedation.

Nursing Implications for CNS Depressants and Muscle Relaxants

Prior to therapy: Obtain thorough history (allergies, medications, health and medical history), baseline vital signs, I&O, and assess for potential contraindications and drug interactions.
Administration: Give hypnotics 30-60 minutes before bedtime for maximum effectiveness.
Patient education: Advise patients to avoid alcohol and other CNS depressants, consult with prescribers before taking any other medications (including OTC), manage rebound insomnia by seeking help when needed, prioritize safety (side rails, bed alarms, no smoking, assist with ambulation).
Monitoring: Therapeutic effects (improved sleep, fewer awakenings, decreased spasticity), adverse effects, age-appropriate considerations.

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Description

This quiz covers the fundamentals of CNS depressants, including sedatives and hypnotics, and their effects on sleep. Learn about the classifications of barbiturates and benzodiazepines, as well as the architecture of sleep such as REM and Non-REM cycles. Test your understanding of these concepts and their implications for treatment.