CHOLINERGIC
DRUGS
Chapter 20
CHOLINERGIC
DRUGS
oDrugs that stimulate the
Parasympathetic Nervous System
(PNS)
oThe PNS is the opposing system
to the sympathetic nervous
system (SNS).
oAlso known as Cholinergic
Agonists or Parasympathomimetics
oMimic effects of the PNS
neurotransmitter acetylcholine
(ACh)
oCholinergic Receptors
oNicotinic Receptors
oMuscarinic Receptors
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Mimic the effects of acetylcholine
CHOLINERGIC
DRUGS:
MECHANISM
OF ACTION
Direct-acting cholinergic agonists
Bind to cholinergic receptors,
activating them
Indirect-acting cholinergic agonists
Stimulate the postsynaptic release of
ACh at the receptor, allowing ACh to
bind & stimulate the receptor
Cholinesterase Inhibitors
Inhibit the enzyme
acetylcholinesterase (cholinesterase),
which breaks down ACh
Reversible
Irreversible
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CHOLINERGIC
DRUGS:
MECHANISM
OF ACTION
AND DRUG
EFFECTS
When ACh binds to receptor,
stimulation occurs.
After binding, permeability of the
cell changes allowing flow of
calcium and sodium into the cells.
Depolarization of cell membrane
occurs causing stimulation of the
effector organ
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CHOLINERGIC DRUGS:
DRUG EFFECTS
Stimulate intestine and bladder
Increase gastric secretions,
gastrointestinal motility & urinary
frequency
Stimulate pupils
Constriction (miosis)
Reduced intraocular pressure
Increased salivation and sweating
Cardiovascular effects
Decreased heart rate
Vasodilation
Respiratory effects
Bronchial constriction, narrowed airways
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Direct-acting drugs
CHOLINERGIC
DRUGS:
INDICATIONS
Echothiophate, Carbachol, & Pilocarpine
Reduce intraocular pressure in glaucoma
Useful for intraocular surgery
Topical application
Bethanechol
Increases tone and motility of bladder & GI
tract
Relaxes sphincters in bladder, allowing it to
empty
Helpful for postsurgical atony of the bladder
Oral
Cevimeline
Treat excessive dry mouth
Succinylcholine
Neuromuscular Blocker in General Anesthesia
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CHOLINERGIC
DRUGS:
INDICATIONS
Indirect-acting drugs
Increase ACh concentrations at the
receptor sites, which leads to
stimulation of the effector cells
Cause skeletal muscle contractions
Diagnosis and Treatment of
Myasthenia Gravis
Reverse Neuromuscular Blocking
Drugs
Reverse Anticholinergic Poisoning
Physostigmine
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CHOLINERGIC DRUGS:
ALZHEIMER’S DISEASE
Alzheimer’s Disease
Neurologic disorder
caused by decreased
levels of acetylcholine
Indirect-acting
cholinesterase inhibitor
drugs
Donepezil (Aricept)
Galantamine
(Razadyne)
Rivastigmine (Exelon)
Non-Cholinergic Drug
Memantine
(Namenda)
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CHOLINERGIC DRUGS
CONTRAINDICATIONS
Known drug allergy
GI or genitourinary (GU) tract
obstruction
Bradycardia
Defects in cardiac impulse conduction
Hyperthyroidism
INTERACTIONS
Anticholinergics, antihistamines,
sympathomimetics
Antagonize cholinergic drugs,
resulting in decreased responses
Other cholinergic drugs
Additive effects
Epilepsy
Hypotension
Chronic obstructive pulmonary disease
Parkinson’s disease
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Overstimulation of the PNS
CHOLINERGIC
DRUGS:
ADVERSE
EFFECTS
Cardiovascular
Bradycardia/Tachycardia,
hypotension/hypertension, syncope,
conduction abnormalities (AV block
and cardiac arrest)
CNS
Headache, dizziness, convulsions,
ataxia
Gastrointestinal
Abdominal cramps, increased
secretions, nausea, vomiting
Respiratory
Increased bronchial secretions,
bronchospasms
Misc.
Lacrimation, sweating, salivation, 10miosis
Early signs
Abdominal cramps, salivation, flushing of the skin,
nausea, and vomiting, transient syncope, transient
complete heart block, dyspnea, and orthostatic
hypotension
Circulatory collapse, hypotension, bloody diarrhea,
shock, and cardiac arrest
Alleviated by cholinergic antagonist (atropine) or
adrenergic agonist (epinephrine)
MEMORIZEME
TOXICITY/OVERDOSE:
CHOLINERGIC CRISIS
SLUDGE
Salvation
Lacrimation
Urinary Incontinence
Diarrhea
GI cramps
Emesis
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DRUG
PROFILES
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DIRECT-ACTING
CHOLINERGIC
AGONIST
Urinary Retention
BETHANECHOL
(URECHOLINE)
60 minutes post-administration
Standard Cholinergic
Contraindications, Interactions,
& Adverse Effects
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CHOLINESTERASE
INHIBITOR
DONEPEZIL
(ARICEPT)
Inhibits cholinesterase centrally
in the brain to increase ACh
Mild-Moderate Alzheimer’s
Disease
Galantamine (Razadyne) &
Rivastigmine (Exelon) work
similarly
Drug Interaction:
Anticholinergics & NSAIDs
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NOT A
CHOLINERGIC
DRUG
MEMANTINE
(NAMENDA)
Inhibits activity at a CNS
receptor thought to stimulate
part of the Alzheimer’s Disease
process
Reduces cognitive degeneration
Temporary, but gives some
quality of life and general
functioning for patients
Many of the same side effects
as Cholinergic Drugs, but also
includes Muscle Pain & Fatigue
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INDIRECT-ACTING Pyridostigmine
CHOLINERGIC -Used in Myasthenia Gravis (MG)
to improve muscle strength
DRUGS
PYRIDOSTIGMINE
(MESTINON),
EDROPHONIUM
(TENSILON), &
PHYSOSTIGMINE
(ANTILIRIUM)
Edrophonium
-Used to diagnosis MG
Pyridostigmine, Edrophonium, &
Physostigmine
-Used to reverse effects of
nondepolarizing NMBDs
after surgery
-Tricyclic Antidepressant OD
Treatment
-Antidote for Nondrug
Anticholinergic Agents used
in Chemical Warfare
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HERBAL THERAPY:
GINKGO (GINKGO BILOBA)
Used to prevent memory loss,
peripheral arterial occlusive
disease, vertigo, tinnitus
AEs: GI upset, bleeding, allergic skin
reaction, HA
Drug Interactions: Aspirin, NSAIDs,
Anticoagulants, Antidepressants,
Antihypertensives,
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CHOLINERGIC DRUGS:
NURSING IMPLICATIONS
Assess for allergies, presence of GI or GU obstructions, asthma,
peptic ulcer disease,
and coronary artery disease.
Perform baseline assessment of vital signs and systems
overview.
Medications should be taken as ordered
and not abruptly stopped.
Atropine is the antidote for cholinergics, and it should be
available in the patient’s room for immediate use if needed.
Monitor for adverse effects
CHOLINERGIC DRUGS:
NURSING IMPLICATIONS
Monitor for therapeutic effects:
Alleviated signs and symptoms of myasthenia gravis
Increased muscle strength
In postoperative patients with decreased GI peristalsis,
monitor for:
Increased bowel sounds
Passage of flatus
Occurrence of bowel movements
In patients with Alzheimer’s disease:
Improvement in symptoms
Improvement in mood and decrease in confusion
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