Transcript The Central and Autonomic Nervous Systems

Chapter 13
Drugs Affecting the Autonomic
Nervous System
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 1
Chapter 13
Lesson 13.1
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 2
Learning Objectives
• Differentiate between afferent and efferent
nerve conduction within the central nervous
system
• Explain the role of neurotransmitters at
synaptic junctions
• Name the most common neurotransmitters
known to affect central nervous system
function
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 3
Learning Objectives (cont’d)
• Identify the two major neurotransmitters of the
autonomic nervous system
• Cite the names of nerve endings that liberate
acetylcholine and those that liberate
norepinephrine
• Explain the action of drugs that inhibit the
actions of the cholinergic and adrenergic
fibers
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 4
Learning Objectives (cont’d)
• List the neurotransmitters responsible for
cholinergic activity
• Identify two broad classes of drugs used to
stimulate the adrenergic nervous system
• Name the neurotransmitters that are called
catecholamines
• Review the actions of adrenergic agents to
identify conditions that would be affected
favorably and unfavorably by these
medications
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 5
The Central and Autonomic
Nervous Systems
• Central nervous system (CNS)
 Made up of brain and spinal cord
 Receives signals from sensory receptors
(vision, pressure, pain, cold, warmth, touch,
smell)
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 6
The Central and Autonomic
Nervous Systems (cont’d)
• Peripheral nervous system
 Afferent nerves—transmit signals to the spinal
cord and brain
 Efferent nerves—carry impulses from CNS to
other parts of body. Divided into two parts:
• Motor nervous system—controls skeletal
muscle contractions
• Autonomic nervous system—regulates certain
body functions
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 7
The Central and Autonomic
Nervous Systems (cont’d)
• Neurons—segments that make up each
nerve of the central and peripheral nervous
systems
• Synapse—junction between one neuron and
the next
• Neurotransmitters—chemical substances that
cause transmission of nerve signals or
impulses
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 8
The Central and Autonomic
Nervous Systems (cont’d)
• Common neurotransmitters affecting CNS







Acetylcholine
Norepinephrine
Epinephrine
Dopamine
Glycine
Gamma-aminobutyric acid (GABA)
Glutamic acid
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 9
Autonomic Nervous System
• Controls most tissue function
• Maintains a constant internal environment
(homeostasis) and responds to emergency
situations
• Made up of two major neurotransmitters
 Norepinephrine—liberated by adrenergic
fibers
 Acetylcholine—liberated by cholinergic fibers
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 10
Autonomic Nervous System
(cont’d)
• Cholinergic drugs cause effects in the body
similar to those produced by acetylcholine
• Adrenergic drugs cause effects similar to
those produced by the adrenergic
neurotransmitter
• Anticholinergic agents block or inhibit
cholinergic activity
• Adrenergic blocking agents inhibit the
adrenergic system
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 11
Drug Class: Adrenergic
Agents
• Two broad classes of drugs
 Catecholamines—three occur naturally in the
body and can be synthetically manufactured
• Norepinephrine
• Epinephrine
• Dopamine
 Noncatecholamines—act in a similar way but
more selective for certain types of receptors
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 12
Drug Class: Adrenergic
Agents (cont’d)
• Side effects usually dose related and
resolved when reduced or discontinued
 Side effects to expect—palpitations,
tachycardia, skin flushing, dizziness, tremors,
orthostatic hypotension
 Side effects to report—dysrhythmias, chest
pain, severe hypotension, hypertension,
anginal pain, nausea, vomiting
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 13
Adrenergic Agents
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Slide 14
Chapter 13
Lesson 13.2
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Slide 15
Learning Objectives
• Explain the rationale for use of adrenergic
blocking agents for conditions that have
vasoconstriction as part of the disease
pathophysiology
• Describe the benefits of using betaadrenergic–blocking agents for hypertension,
angina pectoris, cardiac dysrhythmias, and
hyperthyroidism
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 16
Learning Objectives (cont’d)
• Identify disease conditions that preclude the
use of beta-adrenergic–blocking agents
• List the predictable side effects of cholinergic
agents
• Describe the clinical uses of anticholinergic
agents
• List the predictable side effects of
anticholinergic agents
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 17
Drug Class: Alpha- and BetaAdrenergic–Blocking Agents
• Actions—prevent other agents, usually
naturally occurring catecholamines, from
stimulating the specific receptors by blocking
alpha or beta receptors
• Uses
 Alpha blockers used with diseases associated
with vasoconstriction
 Beta blockers used extensively to treat
hypertension
• Used with caution in patients with diabetes or
susceptible to hypoglycemia
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 18
Beta-Adrenergic–Blocking
Agents
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Slide 19
Drug Class: Cholinergic
Agents
• Known as parasympathomimetic agents—
produce effects similar to those of
acetylcholine
• Act directly by stimulating the
parasympathetic nervous system or indirectly
by inhibiting the enzyme that metabolizes
acetylcholine (acetylcholinesterase) once it is
released by the nerve ending
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 20
Drug Class: Cholinergic
Agents (cont’d)
• Side effects to expect
 Nausea, vomiting, diarrhea, abdominal
cramping, dizziness, hypotension
• Side effects to report
 Bronchospasm, wheezing, bradycardia
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Slide 21
Cholinergic Agents
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Slide 22
Drug Class: Anticholinergic
Agents
• Known as cholinergic blocking agents or
parasympatholytic agents
• Actions
 Block action of acetylcholine in the
parasympathetic nervous system
• Uses
 Effective in the treatment of Parkinson’s
disease, GI and ophthalmic disorders,
bradycardia, and genitourinary disorders
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 23
Drug Class: Anticholinergic
Agents (cont’d)
• Side effects to expect
 Blurred vision, constipation, urinary retention,
dryness of the mucosa of the mouth, nose,
and throat
• Side effects to report
 Confusion, depression, nightmares,
hallucinations
Copyright © 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.
Slide 24
Anticholinergic Agents
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Slide 25