Anxiolytic and Hypnotic Agents

Types of Anxiolytic and Hypnotic Agents

• Anxiolytics
  • Prevent feelings of tension or fear
• Sedatives
  • Calm and make patients unaware of the environment
• Hypnotics
  • Cause sleep
• Minor tranquilizers
  • Produce a state of tranquility in anxious patients

States Affected by Anxiolytic and Hypnotic Drugs

• Anxiety
• –Feeling of tension, nervousness, apprehension, or fear involving unpleasant reactions to a stimulus
• Sedation
• –Loss of awareness and reaction to environmental stimuli
• Hypnosis
• –Extreme sedation resulting in further CNS depression and sleep

Sites of Action of Benzodiazepines and Barbiturates

 

 

Benzodiazepines—Actions

• Act in the limbic system and the RAS
• Make GABA more effective
• Cause interference with neurons firing
• Lower doses cause anxiolytic effects
• Higher doses cause sedation and hypnosis

Benzodiazepines—Indications

• Anxiety disorders
• Alcohol withdrawal
• Hyperexcitability and agitation
• Preoperative relief of anxiety and tension

Benzodiazepines—Pharmacokinetics

• Well absorbed from the GI tract
• Peak levels achieved in 30 minutes to 2 hours
• Lipid soluble and well distributed throughout the body
• Cross placenta
• Enter breast milk
• Metabolized in the liver
• Excretion is primarily in the urine

Benzodiazepines—Contraindications & Cautions

• Allergy to benzodiazepines
• Psychosis
• Acute narrow angle glaucoma
• Shock
• Coma
• Acute alcohol intoxication
• Pregnancy

Benzodiazepines—Adverse Effects

• Sedation
• Drowsiness
• Depression
• Lethargy
• Blurred vision
• Confusion
• Dry mouth
• Constipation
• Nausea
• Vomiting
• Hypotension
• Urinary retention

Benzodiazepines—Drug-to-Drug Interactions

• Increase CNS depression when taken with alcohol
• Increase in effect when taken with cimetidine, oral contraceptives, or disulfiram
• Decrease in effect if given with theophylline or ranitidine

Barbiturates

• Act as a general CNS depressant
• Inhibit neuronal impulse conduction in the ascending RAS
• Depress the cerebral cortex
• Alter cerebellar function
• Depress motor output

Barbiturates—Actions

• CNS depressant
• Inhibit neuronal impulse conduction in the ascending RAS
• Depress cerebral cortex
• Depress motor output
• Cause sedation, hypnosis, anesthesia, and coma

Barbiturates—Indications

• Relief of the signs and symptoms of anxiety
• Sedation
• Insomnia
• Preanesthesia
• Seizures

Barbiturates—Pharmacokinetics

• Well absorbed
• Reach peak in 20 to 60 minutes
• Metabolized in the liver
• Excreted in the urine

Barbiturates—Contraindications & Cautions

• Allergy to any barbiturate
• Previous history of addiction to sedative–hypnotic drugs
• Latent or manifest porphyria
• Marked hepatic impairment or nephritis
• Respiratory distress or severe respiratory dysfunction
• Pregnancy

Barbiturates—Adverse Reactions

• CNS depression
• Physical dependency
• Drowsiness
• Somnolence
• Lethargy
• Ataxia
• Vertigo
• Nausea
• Vomiting
• Constipation

Barbiturates—Drug-to-Drug Interactions

• Increase CNS depression when given with alcohol, antihistamines, and other tranquilizers
• Alter response to phenytoin
• MAOs increase serum levels and effect
• Decrease effectiveness of the following drugs:  anticoagulants, digoxin, tricyclic antidepressants, corticosteroids, and oral contraceptives

Other Anxiolytic and Hypnotic Drugs

• Paraldehyde (Paral): sedates patients with delirium tremens or psychiatric conditions characterized by extreme excitement
• Meprobamate (Miltown): manages acute anxiety for up to 4 months
• Chloral hydrate (Aquachloral): produces nocturnal sedation or preoperative sedation

• Glutethimide (generic), zaleplon (Sonata), and zolpidem (Ambien): short-term treatment of insomnia
• Antihistamines (promethazine [Phenergan], diphenhydramine [Benadryl]: preoperative medications, and postoperatively to decrease the need for narcotics
• Buspirone (BuSpar): reduces the signs and symptoms of anxiety without severe CNS and adverse effects

Use of Anxiolytic and Hypnotic Agents Across the Lifespan

Prototype Benzodiazepines Agent

Prototype Barbiturates Agent

Nursing Considerations for Benzodiazepines

• Assessment (history and physical exam)
• Nursing diagnosis
• Implementation
• Evaluation

Nursing Considerations for Barbiturates

• Assessment (history and physical exam)
• Nursing diagnosis
• Implementation
• Evaluation