Unit 5: Sedatives, Hypnotics, and Anti-anxiety Drug Therapy Study Notes

Comprehensive Definitions of Sedatives and Hypnotics

• Sedatives: Pharmacological agents designed to reduce the desire for physical activity and to produce a state of mental relaxation.
• Hypnotics: Pharmacological agents primarily used to induce and maintain sleep.

Barbiturates: Mechanism and Clinical Considerations

• Mechanism of Action (MOA):
  • Barbiturates depress the Central Nervous System (CNS).
  • They mimic Gamma-Aminobutyric Acid (GABA) by increasing chloride influx into the neurons.
  • This lead to hyperpolarization of the nerve membranes, making them less likely to fire.
  • There is a resultant decrease in the activity of the reticular formation.
• Patient Teaching and Side Effects:
  • Sleep Cycle Alteration: Barbiturates disrupt the natural sleep cycle and cause a specific loss of REM (Rapid Eye Movement) sleep, which is essential for mental restoration.
  • REM Rebound: After discontinuing (d/c) the drug, patients may experience increased dreaming and possible nightmares as the brain attempts to "make up" for lost REM sleep.
  • General Side Effects: Dry mouth, lethargy, drowsiness, depressed reflexes, and impaired judgment.
  • Safety Precautions: Caution must be exercised when driving or operating heavy machinery.
  • Monitoring: Healthcare providers must monitor for signs of tolerance and addiction.
  • Drug Interactions: Consumption of alcohol increases the depressive effects of barbiturates.
• Drug Examples: Individual agents are listed in the Unit 5 Drug List.

Nonbenzodiazepines in Sedative-Hypnotic Therapy

• Mechanism of Action (MOA): These agents increase the inhibitory effects of GABA.
• Therapeutic Uses: Uses vary depending on the specific drug but generally include:
  • Decreasing the number of awakenings throughout the night.
  • Increasing total sleep time.
  • Inducing and maintaining sleep.
  • Assisting patients who have difficulty falling asleep.
• Patient Teaching and Side Effects:
  • Common Reactions: Headaches, dizziness, Gastrointestinal (GI) upset, memory disturbance, and confusion.
  • Monitoring: Continuous monitoring for dependence and tolerance is required.
  • Drug Interactions: Alcohol increases the effects of these medications.
  • Specific Clinical Note on Ambien® (Zolpidem): This medication may cause nightmares, night terrors, and sleepwalking (somnambulism).
• Drug Examples:
  • Ambien (Zolpidem tartrate) available in $10\,\text{mg}$ tablets.
  • Refer to the Unit 5 Drug List for additional examples.

Benzodiazepines: Sedative-Hypnotic and Anxiolytic Profiles

• Mechanism of Action (MOA): Benzodiazepines increase the inhibitory activity of GABA. They serve both as sedative-hypnotics and as anti-anxiety (antianxiety) drugs.
• REM Sleep Preservation: Unlike barbiturates, benzodiazepines do not significantly interfere with REM sleep (mental restoration).
• Patient Teaching and Side Effects:
  • Residual Effects: A "hangover effect" is possible following use.
  • General Reactions: Drowsiness, headache, and dizziness.
  • Monitoring: Clinical surveillance for tolerance and dependence is necessary.
  • Drug Interactions: Alcohol consumption increases the clinical effects.
• Drug Examples:
  • Restoril (Temazepam) capsules.
  • Refer to the Unit 5 Drug List for other "pam" and "lam" medications.

General Nursing and Administration Guidelines for Sedative-Hypnotics

• Alcohol Contraindication: Patients must consume no alcohol while on benzodiazepines or barbiturates, as alcohol further depresses CNS activity.
• Dosage Frequency: These medications should often be taken on an "as needed" (prn) basis.
• Risks of Chronic Use: Long-term use may lead to dependency and tolerance. Abrupt discontinuation (d/c) can result in withdrawal symptoms.

Pathophysiology and Clinical Criteria for Anxiety (DSM-5)

• Definition: Anxiety is characterized by an unpleasant feeling, uneasiness, fear, or worry occurring more days than not for at least $6\,\text{months}$.
• Physiological Indicators: Increased activity in the sympathetic nervous system, limbic system, and reticular formation.
• DSM-5 Diagnostic Criteria: For a diagnosis, $3$ out of the following $6$ symptoms are required in adults (only $1$ is required in children):
  1. Restlessness, feeling keyed up or on edge.
  2. Being easily fatigued.
  3. Difficulty concentrating or the mind going blank.
  4. Irritability.
  5. Muscle tension.
  6. Sleep disturbance (difficulty falling/staying asleep, or restless, unsatisfying sleep).
• Functional Impact: The condition must cause significant distress or impairment in social, occupational, or other important areas of functioning.
• Biochemical Theory: Imbalances are thought to involve various neurotransmitters, including GABA, 5HT (Serotonin), DA (Dopamine), and NE (Norepinephrine).

Multi-functional Mechanism of Benzodiazepines

Benzodiazepines act on multiple regions of the nervous system to produce diverse therapeutic effects:

• GABA / CNS Activity: Increases inhibitory action of GABA and decreases overall CNS activity (Anti-anxiety).
• Limbic System: Decreases activity in the limbic system, leading to decreased emotional and behavioral responses (Anti-anxiety).
• Reticular Formation: Decreases activity in the reticular formation, resulting in decreased alertness and wakefulness (Sedative/Hypnotic).
• Cerebral Cortex and Medulla: Decreases activity in these regions, leading to a decrease in higher learning and motor function (Anticonvulsant).
• Spinal Cord: Decreases activity in the spinal cord, resulting in decreased muscle tone (Skeletal muscle relaxant).

Clinical Use and Profile of Anxiolytics

• Drug Classifications:
  • Certain Antidepressants (SSRI, SNRI, and Miscellaneous agents).
  • Benzodiazepines (used on a prn basis, not typically for maintenance therapy).
  • Nonbenzodiazepines / Azapirones.
• Benzodiazepine Specifics:
  • Categorized into Short-acting and Long-acting.
  • Drug names often end in the suffixes "-pam" or "-lam".
  • Side Effects: Drowsiness, dizziness, confusion, mild GI upset, and long-term memory loss.
  • Safety: Impairs the ability to operate a vehicle; monitor for dependence/addiction.
• Azapirones (Nonbenzodiazepines):
  • MOA: These drugs bind to Serotonin (5HT), reducing levels of 5HT and subsequently reducing the level of anxiety.
  • Clinical Timeline: The full therapeutic effect is reached in $3-4\,\text{weeks}$.
  • Administration: Prescribed as a regular regimen, not as needed (non-prn).
  • Safety Profile: Low abuse potential; no significant interaction with alcohol.
  • Side Effects: Dizziness, lightheadedness, and feeling tired.

Non-pharmacological Therapy for Anxiety

• Resting and counseling groups.
• Listening to music and meditation.
• Exercise and aromatherapy.
• Environmental and atmospheric changes.
• Support from friends and family.

Questions & Discussion

Case Study:

• Scenario: A patient visits his primary care physician reporting significant worry persisting for the past $3\,\text{months}$. The worry originates from job performance (specifically earning a bonus for a retirement nest egg), which has branched into worries about marriage, finances, parenting, and education costs.
• Discussion Questions:
  1. What condition exhibits these symptoms? (Note: While symptoms align with anxiety, the DSM-5 criteria mentioned earlier specify a $6\,\text{month}$ duration; however, the presentation is indicative of an anxiety disorder).
  2. What is a possible drug classification to help treat this patient?
  3. From a holistic approach to care, what non-pharmacological interventions can this patient benefit from?

Unit Resources:

• American Psychiatric Association (APA): www.psychiatry.org
• AACP: www.aacp.com