Parasympathetic Nervous System

Overview

• Known as "rest and digest"
• Effects are different from adrenergic systems

Effects on the Body

• Cardiovascular: Decreases heart rate, potential changes in blood pressure
• Pulmonary: Bronchoconstriction
• Gastrointestinal (GI):
  • Increased peristalsis and motility
  • Increased saliva production
• Liver: Variable glycogen or fat breakdown
• Urinary: Increased urinary output
• Eyes: Pupil constriction

Cholinergic Agonists

• Mnemonic SLUDGE:
  • S: Salivation
  • L: Lacrimation
  • U: Urinary incontinence
  • D: Diarrhea
  • G: GI cramping
  • E: Emesis
• Neurotransmitter: Acetylcholine

Nursing Considerations

• Monitor for therapeutic and side effects
• Patient education on heart rate and blood pressure monitoring
• Safety considerations: swallowing and vision issues

Examples of Drugs

• Donepezil: Increases acetylcholine in the brain, used for mild to moderate Alzheimer's
• Pyridostigmine: Decreases acetylcholinesterase, used for myasthenia gravis and reverses neuromuscular blocking agents

Cholinergic Antagonists (Anticholinergics)

• Effects:
  • "Mad as a hatter": Confusion, CNS effects
  • "Blind as a bat": Pupil dilation, blurred vision
  • "Red as a beet": Vasodilation, facial flushing
  • "Hot as a hare": Hyperthermia
  • "Dry as a bone": Decreased sweating, salivation, and lacrimation

Nursing Considerations

• Monitor heart rate and blood pressure
• Educate patients on drug use and safety

Examples of Drugs

• Atropine: Used for symptomatic bradycardia, pupil dilation, decrease preoperative secretions
• Bentol (Dicyclamine): Decreases GI motility, used for irritable bowel syndrome
• Benstropine: Anticholinergic and antihistamine, helps with Parkinson’s disease
• Toltradine: Mucineric receptor blocker for urinary frequency and urgency
• Scopamine: Antimucineric agent for motion sickness

Drug Classification and Effects

• Sympathetic Nervous System:
  • Adrenergic agonists with anticholinergic effects (fight or flight)
  • Adrenergic antagonists with cholinergic effects (rest and digest)
• Parasympathetic Nervous System:
  • Cholinergic agonists with anti-adrenergic effects
  • Cholinergic antagonists with adrenergic effects

Conclusion

• Understanding drug classifications and their effects on parasympathetic and sympathetic systems is crucial.
• Make use of grids to help classify and understand medications.
• Reach out if clarification or further explanation is needed.