drugs affecting the autonomic nervous system l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Drugs Affecting the Autonomic Nervous System PowerPoint Presentation
Download Presentation
Drugs Affecting the Autonomic Nervous System

Loading in 2 Seconds...

play fullscreen
1 / 58

Drugs Affecting the Autonomic Nervous System - PowerPoint PPT Presentation


  • 692 Views
  • Uploaded on

Drugs Affecting the Autonomic Nervous System. Cholinergic Agents and Cholinergic Blocking Agents. Cholinergic Agents. Drugs that stimulate the parasympathetic nervous system (PSNS) The PSNS is the opposing system to the SNS. Cholinergic Agents. Also known as cholinergic agonists or

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Drugs Affecting the Autonomic Nervous System' - oshin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
drugs affecting the autonomic nervous system

Drugs Affecting the Autonomic Nervous System

Cholinergic Agents andCholinergic Blocking Agents

cholinergic agents
Cholinergic Agents
  • Drugs that stimulate theparasympathetic nervous system (PSNS)
  • The PSNS is the opposing system to the SNS
cholinergic agents3
Cholinergic Agents

Also known as

  • cholinergic agonists

or

  • parasympathomimetics
slide4

Instructors may wish to use EIC Image #56:The Parasympathetic and Sympathetic Nervous Systems and Their Relationships to One Another

cholinergic agents5
Cholinergic Agents
  • Mimic the effects of the PSNS neurotransmitter
  • Acetylcholine (ACh)
cholinergic receptors
Cholinergic Receptors

Two types, determined by:

  • Location
  • Action once stimulated

Nicotinic receptors and Muscarinic receptors

nicotinic receptors
Nicotinic Receptors
  • Located in the ganglia of both the PSNS and SNS
  • Named “nicotinic” because can be stimulated by the alkaloid nicotine
muscarinic receptors
Muscarinic Receptors
  • Located postsynaptically:
    • Smooth muscle
    • Cardiac muscle
    • Glands of parasympathetic fibers
    • Effector organs of cholinergic sympathetic fibers
  • Named “muscarinic” because can be stimulated by the alkaloid muscarine
slide9
Instructors may wish to insert EIC Image #57: The Sympathetic, Parasympathetic, and Somatic Nervous Systems

This slide illustrates location of the nicotinic and muscarinic receptors within the PSNS.

adrenergic agents mechanism of action

Lisa L. Hernandez:

Is there copy missing at the end? Inhibiting what?

HHS:

HHS:

Adrenergic Agents: Mechanism of Action
  • Direct-acting (agonist)
    • Bind to cholinergic receptors, causing stimulation
adrenergic agents mechanism of action11
Adrenergic Agents: Mechanism of Action
  • Indirect-acting
    • Inhibit the enzyme “cholinesterase”

Result: more ACh is available at the receptors

indirect acting cholinergic agents cholinesterase inhibitors
Indirect-Acting Cholinergic Agents (Cholinesterase Inhibitors)
  • Reversible
    • Bind to cholinesterase for a period of minutes to hours
  • Irreversible
    • Bind to cholinesterase and form a permanent covalent bond
    • The body must make new cholinesterase
drug effects of cholinergic agents
Drug Effects of Cholinergic Agents
  • Effects seen when the PSNS is stimulated.
  • The PSNS is the “rest and digest” system.
drug effects of cholinergic agents14
Drug Effects of Cholinergic Agents

“SLUDGE”

  • Salivation
  • Lacrimation
  • Urinary incontinence
  • Diarrhea
  • Gastrointestinal cramps
  • Emesis
drug effects of cholinergic agents15
Drug Effects of Cholinergic Agents
  • Stimulate intestine and bladder
    • Increased gastric secretions
    • Increased gastrointestinal motility
    • Increased urinary frequency
  • Stimulate pupil
    • Constriction (miosis)
    • Reduced intraocular pressure
  • Increased salivation and sweating
drug effects of cholinergic agents16
Drug Effects of Cholinergic Agents
  • Cardiovascular effects
    • Decreased heart rate
    • Vasodilation
  • Respiratory effects
    • Bronchial constriction, narrowed airways
drug effects of cholinergic agents17
Drug Effects of Cholinergic Agents
  • At recommended doses, the cholinergics primarily affect the MUSCARINIC receptors.
  • At high doses, cholinergics stimulate the NICOTINIC receptors.
drug effects of cholinergic agents18
Drug Effects of Cholinergic Agents
  • DESIRED EFFECTS: from muscarinic receptor stimulation
  • Many undesirable effects are due to stimulation of the nicotinic receptors
cholinergic agents therapeutic uses
Cholinergic Agents: Therapeutic Uses

Direct-Acting Agents

  • Reduce intraocular pressure
  • Useful for glaucoma and intraocular surgery

Examples: acetylcholine, carbachol, pilocarpine

Topical application due to poor oral absorption

cholinergic agents therapeutic uses20
Cholinergic Agents: Therapeutic Uses

Direct-Acting Agent—bethanechol

  • Increases tone and motility of bladder and GI tract
  • Relaxes sphincters in bladder and GI tract, allowing them to empty
  • Helpful for postsurgical atony of the bladder and GI tract

Oral dose or SC injection

cholinergic agents therapeutic uses21
Cholinergic Agents: Therapeutic Uses

Indirect-Acting Agents

  • Cause skeletal muscle contractions
  • Used for diagnosis and treatment of myasthenia gravis
  • Used to reverse neuromuscular blocking agents
  • Used to reverse anticholinergic poisoning (antidote)

Examples: physostigmine, pyridostigmine

cholinergic agents therapeutic uses22
Cholinergic Agents: Therapeutic Uses

Indirect-Acting Agent—donepezil (Aricept)

  • Used in the treatment of mild to moderate Alzheimer’s disease.
  • Helps to increase or maintain memory and learning capabilities.
cholinergic agents side effects
Cholinergic Agents: Side Effects

Side effects are a result of overstimulation of the PSNS.

  • Cardiovascular:
    • Bradycardia, hypotension, conduction abnormalities (AV block and cardiac arrest)
  • CNS:
    • Headache, dizziness, convulsions
  • Gastrointestinal:
    • Abdominal cramps, increased secretions, nausea, vomiting
cholinergic agents side effects24
Cholinergic Agents: Side Effects

Side effects are a result of overstimulation of the PSNS.

  • Respiratory:
    • Increased bronchial secretions, bronchospasms
  • Other:
    • Lacrimation, sweating, salivation, loss of binocular accommodation, miosis
cholinergic agents interactions
Cholinergic Agents: Interactions
  • Anticholinergics, antihistamines, sympathomimetics
  • Antagonize cholinergic agents, resulting in decreased responses
cholinergic agents nursing implications
Cholinergic Agents: Nursing Implications
  • Keep in mind that these agents will stimulate the PSNS and mimic the action of ACh.
  • Assess for allergies, presence of GI or GU obstructions, asthma, peptic ulcer disease, or coronary artery disease.
  • Perform baseline assessment of VS and systems overview.
cholinergic agents nursing implications27
Cholinergic Agents: Nursing Implications
  • Medications should be taken as ordered and not abruptly stopped.
  • The doses should be spread evenly apart to optimize the effects of the medication.
  • Overdosing can cause life-threatening problems. Patients should not adjust the dosages unless directed by the physician.
cholinergic agents nursing implications28
Cholinergic Agents: Nursing Implications
  • Encourage patients with myasthenia gravis to take medication 30 minutes before eating to help improve chewing and swallowing.
  • When donepezil is prescribed for Alzheimer’s disease, be honest with caregivers and patients that the drug is for management of symptoms, not for a cure.
  • Therapeutic effects of donepezil may not occur for up to 6 weeks.
cholinergic agents nursing implications29
Cholinergic Agents: Nursing Implications
  • Atropine is the antidote for cholinergics. It should be available in the patient’s room for immediate use if needed.
  • Patients should notify their physician if they experience muscle weakness, abdominal cramps, diarrhea, or difficulty breathing.
cholinergic agents nursing implications30
Cholinergic Agents: Nursing Implications

Monitor for side effects, including:

Increased respiratory Abdominal crampingsecretions

Bronchospasms Dysrhythmias

Difficulty breathing Hypotension

Nausea and vomiting Bradycardia

Diarrhea Increased sweating

Increase in frequency andurgency of voiding patterns

cholinergic agents nursing implications31
Cholinergic Agents: Nursing Implications

Monitor for therapeutic effects:

  • Alleviated signs and symptoms of myasthenia gravis
  • In postoperative patients with decreased GI peristalsis, look for:
    • Increased bowel sounds
    • Passage of flatus
    • Occurrence of bowel movements
  • In patients with urinary retention/hypotonic bladder, urination should occur within 60 minutes of bethanecol administration
cholinergic blocking agents
Cholinergic Blocking Agents
  • Drugs that block or inhibit the actions of acetylcholine (ACh) in the parasympathetic nervous system (PSNS)
cholinergic blocking agents mechanism of action
Cholinergic Blocking Agents: Mechanism of Action
  • Competitive antagonists
  • Compete with ACh
  • Block ACh at the muscarinic receptors in the PSNS
    • As a result, ACh is unable to bind to thereceptor site and cause a cholinergic effect.
cholinergic blocking agents mechanism of action34
Cholinergic Blocking Agents: Mechanism of Action
  • Once these drugs bind to receptors, they inhibit nerve transmission at these receptors.
cholinergic blocking agents chemical class
Cholinergic Blocking Agents: Chemical Class

Natural Synthetic/Semisynthetic

atropine anisotropine clidinium

belladonna dicyclomine glycopyrrolate

hyoscyamine hexocyclium homatropine

scopolamine ipratropium isopropamide

oxybutynin propantheline

tolterodine tridihexethyl

drug effects of cholinergic blocking agents
Drug Effects of Cholinergic Blocking Agents
  • Cardiovascular
    • Small doses: decrease heart rate
    • Large doses: increase heart rate
  • CNS
    • Small doses: decrease muscle rigidity and tremors
    • Large doses: drowsiness, disorientation, hallucinations
drug effects of cholinergic blocking agents38
Drug Effects of Cholinergic Blocking Agents
  • Eye
    • Dilated pupils (mydriasis)
    • Decreased accommodation due to paralysis of ciliary muscles (cycloplegia)
  • Gastrointestinal
    • Relax smooth muscle tone of GI tract
    • Decrease intestinal and gastric secretions
    • Decrease motility and peristalsis
drug effects of cholinergic blocking agents39
Drug Effects of Cholinergic Blocking Agents
  • Genitourinary
    • Relaxed detrusor muscle
    • Increased constriction of internal sphincter
    • Result: urinary retention
  • Glandular
    • Decreased bronchial secretions, salivation, sweating
  • Respiratory
    • Decreased bronchial secretions
    • Dilated bronchial airways
cholinergic blocking agents therapeutic uses
Cholinergic Blocking Agents: Therapeutic Uses

CNS

Decreased muscle rigidity and muscle tremors

  • Parkinson’s disease
  • Drug-induced extrapyramidal reactions
cholinergic blocking agents therapeutic uses41
Cholinergic Blocking Agents: Therapeutic Uses

Cardiovascular

Affect the heart’s conduction system

  • Low doses: slow the heart rate
  • High doses: block inhibitory vagal effects on the SA and AV node pacemaker cells
    • Result: increased heart rate
cholinergic blocking agents therapeutic uses42
Cholinergic Blocking Agents: Therapeutic Uses

Atropine

Used primarily for cardiovascular disorders

  • Sinus node dysfunction
  • Symptomatic second-degree heart block
  • Sinus bradycardia with hemodynamic compromise (advanced life support)
cholinergic blocking agents therapeutic uses43
Cholinergic Blocking Agents: Therapeutic Uses

Respiratory

Blocking the cholinergic stimulation of the PSNS allows unopposed action of the SNS.

  • Results:
    • Decreased secretions from nose, mouth, pharynx, bronchi
    • Relaxed smooth muscles in bronchi and bronchioles
    • Decreased airway resistance
    • Bronchodilation
cholinergic blocking agents therapeutic uses44
Cholinergic Blocking Agents: Therapeutic Uses

Respiratory agents are used to treat:

  • Exercise-induced bronchospasms
  • Chronic bronchitis
  • Asthma
  • Chronic obstructive pulmonary disease
cholinergic blocking agents therapeutic uses45
Cholinergic Blocking Agents: Therapeutic Uses

Gastrointestinal

PSNS controls gastric secretions and smooth muscles that produce gastric motility.

  • Blockade of PSNS results in:
    • Decreased secretions
    • Relaxation of smooth muscle
    • Decreased GI motility and peristalsis
cholinergic blocking agents therapeutic uses46
Cholinergic Blocking Agents: Therapeutic Uses

Gastrointestinal agents are used to treat:

  • Peptic ulcer disease
  • Irritable bowel disease
  • GI hypersecretory states
cholinergic blocking agents therapeutic uses47
Cholinergic Blocking Agents: Therapeutic Uses

Genitourinary

  • Relaxed detrusor muscles of the bladder
  • Increased constriction of the internal sphincter
  • Reflex neurogenic bladder
  • Incontinence
cholinergic blocking agents side effects
Cholinergic Blocking Agents: Side Effects

Body System Side/Adverse Effects

Cardiovascular Increased heart rate, dysrhythmias

CNS CNS excitation, restlessness, irritability, disorientation, hallucinations, delirium

cholinergic blocking agents side effects49
Cholinergic Blocking Agents: Side Effects

Body System Side/Adverse Effects

Eye Dilated pupils, decreased visual accommodation, increased intraocular pressure

Gastrointestinal Decreased salivation, decreased gastric secretions, decreased motility

cholinergic blocking agents side effects50
Cholinergic Blocking Agents: Side Effects

Body System Side/Adverse Effects

Genitourinary Urinary retention

Glandular Decreased sweating

Respiratory Decreased bronchial secretions

cholinergic blocking agents interactions
Cholinergic Blocking Agents: Interactions
  • Antihistamines, phenothiazines, tricyclic antidepressants, MAOIs
  • When given with cholinergic blocking agents, cause ADDITIVE cholinergic effects, resulting in increased effects
cholinergic blocking agents nursing implications
Cholinergic Blocking Agents: Nursing Implications
  • Keep in mind that these agents will blockthe action of ACh in the PSNS.
  • Assess for allergies, presence of BPH, glaucoma, tachycardia, MI, CHF, hiatal hernia, and GI or GU obstruction.
  • Perform baseline assessment of VS and systems overview.
cholinergic blocking agents nursing implications53
Cholinergic Blocking Agents: Nursing Implications
  • Medications should be taken exactly as prescribed to have the maximum therapeutic effect.
  • Overdosing can cause life-threatening problems.
  • Blurred vision may cause problems with driving or operating machinery.
  • Patients may experience sensitivity to light and may want to wear dark glasses or sunglasses.
cholinergic blocking agents nursing implications54
Cholinergic Blocking Agents: Nursing Implications
  • When giving ophthalmic solutions, apply pressure to the inner canthus to prevent systemic absorption.
  • Dry mouth may occur; can be handled by chewing gum, frequent mouth care, and hard candy.
  • Check with physician before taking any other medication, including OTC medications.
  • ANTIDOTE for atropine is physostigmine salicylate (Antilirium).
cholinergic blocking agents nursing implications55
Cholinergic Blocking Agents: Nursing Implications
  • Anticholinergics may lead to higher risk for heat stroke due to effects on heat-regulating mechanisms.
  • Teach patients to limit physical exertion, and avoid high temperatures and strenuous exercise.
  • Emphasize the importance of adequate fluid and salt intake.
cholinergic blocking agents nursing implications56
Cholinergic Blocking Agents: Nursing Implications
  • Patients should report the following to their physician: urinary hesitancy and/or retention, constipation, palpitations, tremors, confusion, sedation or amnesia, excessive dry mouth (especially if they have chronic lung infections or disease), or fever
cholinergic agents nursing implications57
Cholinergic Agents: Nursing Implications
  • Monitor for therapeutic effects:
  • For patients with Parkinson’s disease: fewer tremors and decreased salivation and drooling
  • For patients with peptic ulcer disease: decreased abdominal pain
cholinergic blocking agents nursing implications58
Cholinergic Blocking Agents: Nursing Implications

Monitor for side effects, including:

Constipation Tachycardia

Tremors Confusion

Hallucinations Sedation

Urinary retention Hot, dry skin

Fever

CNS depression (occurs with large doses of atropine)