Transcript Pharmacology

Chapter 30
Agents Used in
Musculoskeletal
Disorders
Skeletal Muscle
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Also called striated muscle; is
attached to the skeleton
Contraction is under voluntary control
Contraction controlled by the nervous
system
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Agents Used in Musculoskeletal
Disorders
Nerve impulses travel down the motor
neurons of the nervous system
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Cause skeletal muscle contraction
The neuromuscular junction contains the
terminal of a motor neuron and a muscle
fiber
Motor axon terminals contain thousands of
vesicles filled with acetylcholine
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Classes of Musculoskeletal Drug
Agents
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Neuromuscular blocking agents
Centrally acting skeletal muscle
relaxants
Direct-acting skeletal muscle relaxants
Skeletal muscle stimulants
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Neuromuscular Blocking Agents
Action
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Block the action of acetylcholine
Mimic acetylcholine action and prevent
cholinesterase from working; the muscle
becomes overtired and the client is unable
to use the muscle
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Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.
(continued)
Neuromuscular Blocking Agents
Relax or paralyze the skeletal muscles
Used for:
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Surgery
Electroconvulsive therapy
Endotracheal intubation
Tetanus treatment
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Centrally Acting Skeletal
Muscle Relaxants
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Depress the CNS in the brainstem, basal
ganglia, and neurons of the spinal cord
Do not act on the neuromuscular junction
Relieve pain associated with skeletal
muscle spasms—cerebral palsy
High risk: sedation
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Direct-Acting Skeletal
Muscle Relaxants
Inhibit calcium release from the skeletal
muscles
Muscle is then less responsive
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Dantrolene acts directly on skeletal muscle;
relaxes spastic muscle
Used in the treatment of multiple sclerosis,
cerebral palsy, and stroke
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Skeletal-Muscle Stimulants
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Correct muscular weakness such as
myasthenia gravis
Inhibits the action of anticholinesterase;
more acetylcholine is available to cause
and maintain the muscle contraction
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Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.
(continued)
Skeletal-Muscle Stimulants
Side effects/adverse effects
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Caused by unusual cholinergic activity
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Increased salivation
Diarrhea
Intestinal cramping
Bradycardia
Miosis
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Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.