Chapter 7 Cholinoceptor-Blocking Drugs (?) -N -Cholinoceptor blockers

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Chapter 7 Cholinoceptor-Blocking Drugs (?) -N
-Cholinoceptor blockers

• Zhang bin
• Institute of Pharmacology
• School of Medicine
• Shandong University

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Nicotinic cholinoceptor- blocking drugs

• NN-R antagonists
• (ganglionic blocking drugs)
• NM-R antagonists
• (neuromuscular blocking drugs )
• (Skeletal muscle relaxants)

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Section1 NN-R antagonists (ganglionic blocking
drugs)

• Mecamylamine(????,???)
• Trimethaphan(????,???)

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NN-R antagonists

• Characteristics
• Co-innervation and dominant theory
• Blood vessel vasodilation, peripheral resistance
  decrease, blood pressure decrease.
• Glands, eye, GI, bladder dry mouth, mydriasis,
  constipation, urinary retention
• Clinical use HBP

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Section2 NM-R antagonists (Skeletal muscle
relaxants) (neuromuscular blocking drugs )

• Depolarizing skeletal muscle relaxants
• succinylcholine
• Nondepolarizing skeletal muscle relaxants
• D-tubocurarine

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Depolarizing skeletal muscle relaxants
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Mechanism Two-phase blockPhase 1 durable
depolarizing blockPhase 2 NM receptor
desensitization
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Depolarizing skeletal muscle relaxants

• Characteristics of Action
• (1)Muscle fasciculation (????)
• (2)Tachyphylaxis (?????)
• (3)Cant be antagonized by AChEI
• (4)have no ganglionic blocking actions at
  therapeutic dose
• (5) rapid onset and short duration

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succinylcholine (????,scoline,???)

• (1)Onset rapid(1), Emax 2, short duration(5)
• (2) Neck and limbs
• (3)pseudocholinesterase
• Uses
• 1.assistant agents of anesthetics
• 2.bronchial cannulation,bronchoscopy
• oesophagoscop(???)

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Adverse reactions

• (1)  asphyxy(??) respiratory muscle
  paralysis
• genetic pseudo-ChE low patients
• anti-AChE agents
• local anesthetics and aminoglycosides
• (2) Muscle fasciculation
• (3) Elevation of extracellular K
• (4) CVS complex
• (5) Malignant hyperpyrexia(????)
• 
  idiosyncrasy (?????)
• (6) increase histamine release

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Malignant hyperpyrexia

• ???????????????(??????)?????????,?????????????????
  ??(?????????,??????????,??????????????)
• ????(???)???????????????,????????????????????

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Nondepolarizing muscular relaxants(competitive
neuromuscular blockers)
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• Mechanisms
• NM-R competitive
• antagonist

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Characteristics of Action

• (1) no fasciculation
• (2) Antagonized by AChEI
• (3) slow onset and long duration
• (4) NN blockade at therapeutic dose

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d-tubocurarine(????)

• Actions
• muscle relaxant
• block ganglionic
• release histamine
• Uses
• assistant agents of anesthetics

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Other drugs

• benzylisoquinolines (??????)
• Atracurium (???? )
• Doxacurium (??? )
• Mivacurium (??? )
• ammoniosteroids(?????)
• Pancuronium (??? )
• Pipecuronium (??? )
• Rocuronium (??? )
• Vecuronium (??? )