1. Cholinergic Drugs

2. Cholinergic Drugs
 Describe the cholinergic drug effects on major
body systems.
 Discuss the nursing process related to the care
of patients receiving cholinergic drugs for select
problems.

3. Cholinergic Drugs
 Drugs that stimulate the
parasympathetic nervous system (PSNS)
 opposing system to the SNS
 Known as: cholinergic agonists or parasympathomimetics
 Mimic the effects of the PSNS neurotransmitter:
acetylcholine (Ach)
 Two types of Receptors:
 determined by: Location & Action once stimulated
 Muscarinic receptors – recommended doses with desired effect
 Nicotinic receptors – higher doses with undesirable effects

5. Cholinergic Drugs
Mechanism of Action
 Direct-acting cholinergic agonists
 Bind to cholinergic receptors, activating them
 Indirect-acting cholinergic agonists
 Inhibit the enzyme acetylcholinesterase - preventing,
which breaks down ACh - more ACh is available at the
receptors
 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 to break these
bonds

6. Cholinergic Drugs
“rest and digest” system
“SLUDGE”
 Salivation
 Lacrimation
 Urinary incontinence
 Diarrhea
 Gastrointestinal cramps
 Emesis

7. Cholinergic Drugs
Drug Effects
 Stimulate intestine and bladder
 Increased gastric secretions
 Increased gastrointestinal motility
 Increased 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

8. Cholinergic Drugs
Drugs
 Bethanechol (Urecholine) – urinary retention
 Cevimeline (Evoxac) – Xerostomia
 Memantine (Namenda) – Alzheimer’s dementia
 Physostigmine (Antilirium) – reversal of
anticholinergic drugs effects
 Pyridostigmine (Mestinon) – Myasthenia gravis

9. Cholinergic Drugs
Indications
Direct-acting drugs
 Reduce intraocular pressure
 Topical useful for glaucoma and intraocular surgery
 pilocarpine

10. Cholinergic Drugs
Indications
Direct-acting drug—bethanechol (Urecholine)
 Increases tone and motility of bladder and GI tract
 Relaxes sphincters in bladder and GI tract, allowing
them to empty
 Used to reverse postsurgical atony of the bladder
and GI tract
 Oral dose or SC injection

11. Cholinergic Drugs
Indications
Indirect-acting drugs
 Cause skeletal muscle contractions
 Used for diagnosis and treatment of myasthenia gravis
 Pyridostigmine (Mestinon) – Myasthenia gravis
 Used to reverse neuromuscular blocking drugs/anesthesia
 Used to reverse anticholinergic poisoning (antidote)
 Examples: physostigmine (Antilirium)

12. Cholinergic Drugs
Indications
Indirect-acting drugs—cevimeline (Evoxac)
 Used to treat xerostomia (dry mouth)
resulting from Sjögren’s syndrome

13. Cholinergic Drugs
Adverse Effects
Adverse 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
 Respiratory
 Increased bronchial secretions, bronchospasm
 Other
 Lacrimation, sweating, salivation, loss of binocular accommodation,
miosis

14. Cholinergic Drugs
Interactions
 Anticholinergics, antihistamines,
sympathomimetics
 Antagonize cholinergic drugs, resulting in
decreased responses
 Other cholinergic drugs
 Additive effects

15. Cholinergic Drugs
Nursing Implications
 Assess for allergies, presence of GI or GU obstructions, asthma, peptic
ulcer disease, or coronary artery disease
 Perform baseline assessment of vital signs and systems overview
 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. Only physicians
should adjust the dosages

16. Cholinergic Drugs
Nursing Implications
 Encourage patients with myasthenia gravis to take
medication 30 minutes before eating to help improve
chewing and swallowing
 When cholinergic drugs are prescribed for Alzheimer’s
disease, be honest with caregivers and patients that the
drugs are for management of symptoms, not a cure
 Therapeutic effects of anti-Alzheimer’s drugs may not
occur for up to 6 weeks

17. Cholinergic Drugs
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
bethanechol administration
 ALSO monitor for adverse effects

19. Drugs Affecting the Parasympathetic
Nervous System
Parasympathetic Nervous System
 Neurotransmitter is ACH
 The receptors are called cholinergic receptors.
 Drugs that bind to cholinergic receptors and produced effects
similar to ACH are referred to as cholinergic drugs.

20. Drugs Affecting the Parasympathetic
Nervous System
ACH ACH ACH
ACH ACH
ACH ACH ACH
ACH
ACH
ACH
ACH ACH ACH
Acetylcholinesterase

21. Drugs Affecting the Parasympathetic
Nervous System
Receptors
Muscarinic Receptors Nicotinic Receptors
N-1 N-2

22. Drugs Affecting the Parasympathetic
Nervous System
Nicotinic Receptors
Nicotinic-I Receptors Nicotinic-II Receptors
Found at ganglions of
Found at Neuromuscular junction of
Sympathetic and Parasympathetic
Skeletal muscles.
Post- ganglionic fibers

23. Drugs Affecting the Parasympathetic
Nervous System
Ganglion, Nicotinic I receptor
Sympathetic Fibers
Pre-ganglionic Post-ganglionic Fiber
Fiber
Adrenergic Receptor
Ganglion, Nicotinic I receptor
Parasympathetic Fibers
Pre-ganglionic Fiber Post-ganglionic Fiber
Muscarinic Receptors
Somatic Fibers
Nicotinic II Receptors

24. Drugs Affecting the Parasympathetic
Nervous System
Nicotine
 Alkaloid obtained from tobacco.
 Stimulate the NI receptors at low doses.
 Block the NII receptors at high doses.

25. Drugs Affecting the Parasympathetic
Nervous System
Nicotinic I
Drugs
Ganglionic Ganglionic
Stimulants Blockers

26. Drugs Affecting the Parasympathetic
Nervous System
Muscarinic Receptors
 Found at the parasympathetic
postganglionic nerve endings
 Drugs that act like ACH at these receptors
are referred to as cholinergic or muscarinic
drugs.
 Drugs that block ACH at the muscarinic
receptors are referred to as anticholinergic
or antimuscarinic drugs.

27. Drugs Affecting the Parasympathetic
Nervous System
Parasympathetic
Drugs
Cholinergic Anti-cholinergic
Drugs Drugs

28. Drugs Affecting the Parasympathetic
Nervous System
Cholinergic
Drugs
Direct Acting Indirect Acting
Cholinergic Drugs Cholinergic Drugs

29. Drugs Affecting the Parasympathetic
Nervous System
Direct Acting Cholinergic Drugs
 Bind to muscarinic receptors.
 Produces ACH like effect.
 Slowly inactivated by
acetylcholinesterase.

30. Drugs Affecting the Parasympathetic
Nervous System
Pharmocological Effects
 Increase GI secretion and motility
 Increase in genitourinary activity.
 Bronchoconstriction

31. Drugs Affecting the Parasympathetic
Nervous System
Pharmocological Effects
 Miosis
 Vasodilatation (lower BP)
 Decrease heart rate.

32. Drugs Affecting the Parasympathetic
Nervous System
Direct Acting Main Use
Acetylcholine Miotic
Bethanecol Nonobstructive urinary
retention
Carbachol Treatment of glaucoma
Methacholine Miotic
Pilocarpine Treatment of glaucoma

33. Drugs Affecting the Parasympathetic
Nervous System
Indirect Acting
Cholinergic Drugs
(Anticholinesterases)
Reversible Irreversible
Inhibitors Inhibitors

34. Drugs Affecting the Parasympathetic
Nervous System
ACH ACH
ACH
ACH ACH ACH
ACH ACH
ACH
ACH
ACH
ACH ACH ACH
Acetylcholinesterase
Anticholinesterases

35. Drugs Affecting the Parasympathetic
Nervous System
Reversible Inhibitors
 Blocks cholinergic and nicotinic
receptors.
 Use in the diagnosis and treatment of
myasthenia gravis.

36. Drugs Affecting the Parasympathetic
Nervous System
Irreversible Inhibitors
 Derivatives of organophosphate
compounds.
 Widely used as insecticides,
pesticides and chemical warfare
agents.
 Long duration of action

37. Drugs Affecting the Parasympathetic
Nervous System
Clinical Use
 Topical use in glaucoma
 Treatment of myasthenia gravis
 Treatment of urinary retention and intestinal stasis

38. Drugs Affecting the Parasympathetic
Nervous System
Clinical Use
 Treatment of Alzheimer’s disease.
 Antidote to skeletal muscle blockers.
 Antidotes to anticholinergic drug
poisoning.

39. Drugs Affecting the Parasympathetic
Nervous System
Indirect-Acting
Cholinergic Drug
Reversible Irreversible
Ambenonium Isoflurophate
Edrophonium
Neostigmine
Physostigmine
Pyridostigmine

40. Drugs Affecting the Parasympathetic
Nervous System
Adverse and Toxic Effect
 Nausea
 Vomiting
 Diarrhea
 Blurred vision

41. Drugs Affecting the Parasympathetic
Nervous System
Adverse and Toxic Effect
 Excessive sweating
 Muscular tremors
 Bronchoconstriction
 Bradycardia

42. Drugs Affecting the Parasympathetic
Nervous System
Adverse and Toxic Effect
 Hypotension
 Mucular paralysis
 Respiratory arrest

43. Drugs Affecting the Parasympathetic
Nervous System
Cholinergic Crisis
 Excessive drug dosage in patients with
myasthenia gravis.
 High concentration of ACH causes
excessive stimulation of the muscarinic
receptors.
 High concentration of ACH causes
blockade of nicotinic receptor.

44. Drugs Affecting the Parasympathetic
Nervous System
Treatment
 Stop anticholinesterase drug administration.
 Give atropine to block the effect of excess muscarinic
stimulation

45. Drugs Affecting the Parasympathetic
Nervous System
Cholinergic Crisis
 Excessive exposure to sprays containing
derivatives of irreversible
anticholinesterase.
 High concentration of ACH causes
excessive stimulation of the muscarinic
receptors.
 High concentration of ACH causes
blockade of nicotinic receptor.

46. Drugs Affecting the Parasympathetic
Nervous System
Treatment
 Remove person from the exposure.
 Give Pralidoxime to reactivate the anticholinesterase enzyme.
 Give atropine to block the effect of excess muscarinic
stimulation

47. Drugs Affecting the Parasympathetic
Nervous System
Anticholinergic Drugs
 Binds to muscarinic receptors.
 Act by competitive antagonism of ACH.
 Prototype drugs: Belladonna alkaloids,
atropine and scopolamine

48. Drugs Affecting the Parasympathetic
Nervous System
Pharmacological Action
 Increase heart rate.
 Increase the secretions of the respiratory
tract and may cause bronchoconstriction.
 Reduce salivary and GI tract.
 Inhibit urinary peristalsis and voiding of
urine.

49. Drugs Affecting the Parasympathetic
Nervous System
Pharmacological Action
 Depressant effects on the CNS causing
drowsiness and sedation.
 At high doses cause both stimulation and
depression of the CNS
 At toxic doses excitation, delirium,
hallucination and profound CNS depression
leading to respiratory arrest and death.

50. Drugs Affecting the Parasympathetic
Nervous System
Ocular Effect
 Mydriasis
 Cycloplegia
 Increases Intraocular
pressure.

51. Drugs Affecting the Parasympathetic
Nervous System
Adverse and Toxic Effect
 Cause by excessive blockage of the Parasympathetic Nervous
System.
 Dry mouth.
 Visual disturbances
 Urinary retention
 Constipation.

52. Drugs Affecting the Parasympathetic
Nervous System
Adverse and Toxic Effect
 Dryness of the skin
 Flushing
 Hyperpyrexia
 CNS stimulation and depression

53. Drugs Affecting the Parasympathetic
Nervous System
Anticholinergic Drugs
Belladonna Alkaloids Synthetic Drugs
Atropine Semisynthetic Drug Diclyclomine
Scopolamine Isopropamide
Hyoscyamine Homatropine Propantheline
Methantheline

55. Drugs Affecting the Sympathetic
Nervous System
Release
Adrenergic Receptor
NE NE NE
MAO NE NE Involuntary Muscle
Membrane
Metabolism Reuptake
NE
Adrenergic nerve ending

56. Drugs Affecting the Sympathetic
Nervous System
Adrenergic
Receptors
Alpha Beta
Receptors Receptors
Beta 1 Beta 2
Receptors Receptors

57. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic Receptors
 Found predominantly on smooth muscle
membrane.
 When stimulated by NE or EPI produce
contraction.
 Produces vasoconstriction of most blood
vessels.

58. Drugs Affecting the Sympathetic
Nervous System
Beta-adrenergic Receptors
 Found on both cardiac and some smooth
muscle membranes.
 In the heart, beta 1 receptors
predominates.
 When stimulated by NE or EPI, they
increase heart rate and force of
contraction.

59. Drugs Affecting the Sympathetic
Nervous System
Beta-adrenergic Receptors
 Found on smooth muscle in the bronchus and
smooth muscles of blood vessels supplying
muscle and the heart.
 Stimulated with EPI result in relaxation.

60. Drugs Affecting the Sympathetic
Nervous System
Beta-adrenergic Receptors
 In smooth muscle, beta 2 receptors
predominates.
 When stimulated by EPI, they produces muscle
relaxation.
 Found in smooth muscles of blood vessels
supplying skeletal muscle and the coronary
arteries.
 Found on smooth muscle in the bronchial tree.

61. Drugs Affecting the Sympathetic
Nervous System
Beta 1
Receptors
Found on smooth
muscle in the heart
Increase heart rate and
force of contraction.

62. Drugs Affecting the Sympathetic
Nervous System
Beta 2
Receptors
Found on smooth
Found on smooth muscle
muscle in the
of blood vessels supplying
bronchial tree.
skeletal muscle and the heart.
Vasodilatation. Bronchodilation.

63. Drugs Affecting the Sympathetic
Nervous System
Sympathetic
Drugs
Sympathomimetic Sympatholytic
Drugs Drugs

64. Drugs Affecting the Sympathetic
Nervous System
Sympathomimetic
Drugs
Alpha-adrenergic Beta- adrenergic
Selective Beta 1 Selective Beta 2
Adrenergic. Adrenergic.

65. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic Drugs
 NE prototype
 Most important clinical effect is contraction
of smooth muscles.
 Vasoconstriction of most blood vessels
leading to increase in blood pressure.
 Contraction of sphincter muscles.

66. Drugs Affecting the Sympathetic
Nervous System
Contraction of
Sphincter Muscles
GI tract Urinary Tract Eyes
Inhibits movement of Restricts passage
Mydriasis
intestinal contents of urine.

67. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic Drugs
Clinical Indications
 Hypotensive states
 Decongestion
 Pupillary dilation

68. Drugs Affecting the Sympathetic
Nervous System
Adverse Effects
 Hypertensive crisis
 Cerebral hemorrhage
 Cardiac arrhythmias
 Irritation of the nasal sinuses or
eye.

69. Drugs Affecting the Sympathetic
Nervous System
Drug Main Use
Epinephrine To increase BP
Norepinephrine To increase BP
Pseudoephedrine Nasal decongestion
Tetrahydrozoline Ophthalmic decongestion

70. Drugs Affecting the Sympathetic
Nervous System
Beta-adrenergic Drugs
 Stimulation of the heart
 Bronchodilation
 Relaxes uterine smooth muscle

71. Drugs Affecting the Sympathetic
Nervous System
Drugs Classification Main Use
Epinephrine Alpha, Beta-1 Vasopressor, Cardiac
and Beta-2 stimulant, bronchodilator.
Isoproterenol Beta-1 and Beta- Cardiac stimulant,
2 bronchodilator.
Albuterol Beta-2 Bronchodilator.
Ritodrine Beta-2 Arrest preterm labor.

72. Drugs Affecting the Sympathetic
Nervous System
Epinephrine
 DOC for allergic reactions
 Use in combination with local anesthetics.
 Used as a cardiac stimulant in emergencies.
 Use in the treatment of asthma.

73. Drugs Affecting the Sympathetic
Nervous System
Adverse Effects
 CNS stimulation – tremor, restlessness,
anxiety (beta effect)
 Over-stimulation of the heart (beta 1 effect)
 Lower blood pressure (beta 2 effect)

74. Drugs Affecting the Sympathetic
Nervous System
Dopamine
 Neurotransmitter in the brain.
 Precursor in the synthesis of NE
 Stimulates dopaminergic, beta-1 and alpha-
receptors.
 Use as a drug.
 Dobutamine similar to dopamine but with
more Beta-1 effect.

75. Drugs Affecting the Sympathetic
Nervous System
NE
NE
NE
MAO
Tyrosine DOPA Dopamine
NE
NE

76. Drugs Affecting the Sympathetic
Nervous System
DOPAMINE RECEPTORS EFFECTS
DOSE STIMULATED
Low dose Stimulate dopaminergic Increased renal blood flow
receptors in the renal and and vasodilatation.
mesenteric blood vessels.
Moderate dose Stimulates beta-1 Increase myocardial
receptors in the heart. contractility.
Higher dose Stimulate alpha-receptors Produces vasoconstriction.

77. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic blocking drugs
 Binds to Alpha receptors
 Antagonizes the effects of NE and EPI
 Leads to a decrease in sympathetic response
 Resulting in vasodilatation and thus decrease in BP.

78. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic blocking drugs.
Clinical Indications
 Treatment of hypertension.
 Vasodilator in treatment of Raynaud’s disease.
 Diagnosis of Pheochromocytoma.

79. Drugs Affecting the Sympathetic
Nervous System
Alpha-adrenergic blocking drugs.
Adverse Effects
 Constriction of pupils
 Increased GI activity
 Nasal congestion
 Reflex tachycardia ( if BP is lowered too much).

80. Drugs Affecting the Sympathetic
Nervous System
Drugs Main Use
Doxazosin Treatment of Hypertension
Prazosin Treatment of Hypertension
Phentolamine Diagnosis of pheochromocytoma.
Treatment of vascular disease.

81. Drugs Affecting the Sympathetic
Nervous System
Beta-adrenergic blocking drugs.
 Binds to beta receptors
 Antagonizes the effects of NE and EPI
 Leads to a decrease in sympathetic response.
 Resulting in decrease heart rate and force of
contraction.

82. Drugs Affecting the Sympathetic
Nervous System
Beta-blocking
Drugs
Non-selective Selective Beta-1

83. Drugs Affecting the Sympathetic
Nervous System
Nonselective Blockers Main Use
Labetalol Hypertension
Nadolol Hypertension, Angina Pectoris
Pindolol Hypertension
Propanolol Hypertension, Angina Pectoris,
arrhythmhias, migraine
Timolol Hypertension, post myocardial
infarction.

84. Drugs Affecting the Sympathetic
Nervous System
Selective Blockers Main Use
Acebutolol Hypertension, ventricular
arrhythmias.
Atenolol Hypertension, Angina Pectoris
Bisoprolol Hypertension
Esmolol Supraventricular tachycardia
Metoprolol Hypertension, Angina Pectoris

85. Drugs Affecting the Sympathetic
Nervous System
Propranolol
 Decrease heart rate
 Decrease force of contraction
 Decrease rate of conduction
 Resulting decrease in effort and work of the
heart causes a decrease in oxygen consumption.

86. Drugs Affecting the Sympathetic
Nervous System
 Oral and iv preparation
 Drug is carried directly to the liver by the portal system.
 Significant first pass metabolism.
 Lipid soluble and passes into the brain.
 Causes CNS sedation, depression and decreased central
sympathetic activity.

87. Drugs Affecting the Sympathetic
Nervous System
 Used in the treatment of angina, and various
cardiac arrhythmia.
 Adverse effects include nausea, vomiting and
diarrhea, bradycardia with resulting reduced
cardiac function, bronchoconstriction.
 Most serious drug interactions involve
therapy of beta blockers with other drugs that
decrease cardiac function (cardiac glycosides,
anti-arrhythmic drugs and calcium blockers).

88. Drugs Affecting the Sympathetic
Nervous System
Adrenergic neuronal blockers
 Drugs that interfere with the formation
and or storage of NE
 Alpha-methyl dopa
 Reserpine
 Guanethidine

89. Drugs Affecting the Sympathetic
Nervous System
Reserpine
NE
NE
NE
MAO
Tyrosine DOPA Dopamine
NE
NE
Guanethidine
Alpha-methyl dopa

90. Drugs Affecting the Sympathetic
Nervous System
Drugs Mechanism of Action Main Use
Alpha-methyl dopa Blocks formation of Treatment of
Dopamine hypertension
Reserpine Depletes NE storage Treatment of
granule hypertension
Guanethidine Block release of NE Treatment of
and depletes NE hypertension
storage granule