Drugs Acting on the Central and Peripheral Nervous Systems Nursing Pharmacology

Anxiolytic and Hypnotic Agents

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

Sites of Action of Benzodiazepines and Barbiturates
Sites of Action of Benzodiazepines and Barbiturates




  • 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


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


  • 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


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


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


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


  • 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

Use of Anxiolytic and Hypnotic Agents Across the Lifespan
Use of Anxiolytic and Hypnotic Agents Across the Lifespan

Prototype Benzodiazepines Agent

Prototype Benzodiazepines Agent
Prototype Benzodiazepines Agent

Prototype Barbiturates Agent

Prototype Barbiturates 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
Introduction to Nursing Pharmacology Nursing Pharmacology

Drugs and The Body

Drugs and the Body


  • Pharmacodynamics is the science of dealing with interactions between living organisms and foreign chemicals
  • Chemical reactions occur continuously in the body of each living system
  • When other chemicals (drugs) are added to the body, additional effects occur

Drug Actions

  • To replace or act as substitutes for missing chemicals
  • To increase or stimulate certain cellular activities
  • To depress or slow certain cellular activities
  • To interfere with the functioning of foreign cells

Receptor Cells

  • Receptor site reacts to certain chemicals
  • The better the fit between receptor site and chemical, the more pronounced the reaction
  • Enzymes within the body are needed to break down the chemicals to open up the receptor site

Lock & Key

Drugs and The Body: Lock and Key
Drugs and The Body: Lock and Key


  • Drugs can interfere with the enzymes that may be catalysts for chemical reactions
  • Enzymes produce a cascade effect


  • Onset of drug action
  • Drug half-life
  • Timing of the peak effect
  • Duration of drug effects
  • Metabolism or biotransformation of the drug
  • Site of excretion

The Processes by Which Drugs Are Handled in the Body

The Processes by Which Drugs Are Handled in the Body
The Processes by Which Drugs Are Handled in the Body


  • Critical concentration
    • The amount of a drug that is needed to cause a therapeutic effect
  • Loading dose
    • A higher dose than that usually used for treatment
  • Dynamic equilibrium
    • The actual concentration that a drug reaches in the body

Dynamic Equilibrium

  • The actual amount of drug that reaches the body results in a dynamic equilibrium
  • Dynamic equilibrium is affected by:
    • Absorption
    • Distribution
    • Biotransformation
    • Excretion


  • Administration
    • Affected by route of administration
    • Oral medications affected by presence of food in the stomach
  • First-pass effect
    • Medications are extensively metabolized by the liver

Factors Affecting Absorption

Factors That Affect Absorption of Drugs
Factors That Affect Absorption of Drugs


  • Protein binding
  • Blood–brain barrier
  • Placenta/breast milk


  • The liver is the single most important site for biotransformation (metabolism)
  • This process breaks down medications
  • It helps to prevent medications from causing adverse effects on the body


  • Removal of drugs from the body
  • Kidneys play the most important role in the excretion of medication


  • Half-life is the time it takes for the amount of drug in the body to decrease to one-half the peak level
  • Half-life is affected by the absorption, distribution, metabolism, and excretion





Calculating Half-Life

Focus on Calculations
Focus on Calculations

Factors Influencing Drug Effects

  • Weight
  • Age
  • Gender
  • Physiologic factors
  • Pathologic factors
  • Genetic factors
  • Immunologic factors
  • Psychological factors
  • Environmental factors
  • Drug tolerance
  • Cumulative effect

Drug-to-Drug Interactions

  • Can occur any time two or more drugs are taken together
  • Can occur at:
    • Site of absorption
    • During distribution
    • During biotransformation
    • During excretion
    • At the site of action

Drug–Food Interaction

  • Certain foods interact with drugs
  • Drugs are best taken on an empty stomach

Drug–Laboratory Test Interaction

  • Drugs may alter the results of lab testing
  • Laboratory tests may be used to monitor the effects of other medications
204 RLE Procedures



Maintaining an optimum hygienic of a surgically created opening between colon and abdominal wall that allows fecal elimination.


  • To allow fecal elimination
  • To prevent infection on operative site
  • To facilitate accommodation of excretion and avoid spillage of contents
  • To collect effluent for assessment of the amount and type of output
  • To minimize odors for the client’s comfort and self-esteem


  • Obtain doctor’s order
  • Explain the procedure to the patient
  • Provide privacy
  • Use universally precautions in handling body secretions
  • Uphold aseptic technique


  • Large tail closure                                     Irrigator bag or enema bag
  • Water soluble lubricant                        Cone tip or soft rubber catheter
  • Cleansing agent                                         no. 22 or no. 24 with shield
  • Clean gloves
  • Skin protectant
  • Irrigation sleeve

1. Check doctor’s order and explain procedure to the patient.

Rationale: Relieve anxiety and promote compliance

2. Select a consistent time of the day that best fit patient lifestyle to irrigate free from distraction.

Rationale: Establish regularity.

3. Have patient sit on a chair or commode. Provide privacy.

Rationale: To be in comfortable position.

4. Hang the irrigating reservoir with prescribed solution so bottom of reservoir is at the level of patients shoulder and above the stoma.

Rationale: Height regulates pressure of irrigant.

5. Wear gloves and mask

Rationale: Prevent transmission of microorganism and inhalation of fecal odor.

6. Remove pouch or covering of stoma and apply irregular sleeve, directing the open tail into the commode.

Rationale: Allows water and feces to flow directly into the commode.

7. Open tubing clamp or irrigating reservoir to release a small amount of solution into the commode.

Rationale: Removes air from the set-up; prevent air to enter into the colon and cause cramping again.

8. Lubricate the tip of the cone/catheter, insert about 3 inches into the stoma. Hold cone/shield gently but firmly  to prevent back-flow of water.

Rationale: Prevent intestinal perforation and irritation of mucus membrane.

9. Allow water to enter  colon slowly over 5-10 minutes period. If cramping occurs, slow the flow rate or clamp tubing to allow cramping to subside.

Rationale: Slow relaxes bowel to facilitate passage of catheter.

10. Hold cone for 10 sec. after water is instilled, then gently remove cone from stoma.

Rationale: Cramping occur if too rapid flow, cold water excess solution on a colon ready to function.

11. As feces and water flow down sleeve, periodically rinse sleeve with water. Allow 10-15 min  for most of the return, then dry sleeve tail and apply tail closure.

Rationale: To cleanse the sleeve for patency.

12. Leave sleeve in place for approximately 20 more minutes while patient gets up and moves around.

Rationale: For patient’s comfort.

13. When returns are complete, clean stoma area with mild soap and water, pat dry, reapply pouch.

Rationale: To cleanse the stoma and make the pouch available for use.

14. Leave patient dry and comfortable.

Rationale: For patient comfort.

15. Do aftercare of equipment with soap and water, dry and store in well-ventilated area.

Rationale: To be ready for the next use.

16. Chart procedure done, reaction of patient.

Rationale: For documentation purposes.


Kozier, Barbara, Fundamentals of Nursing Philippines: Pearson Education South Asia PTE LTD.2004. pp. 1247-1250