Pharmacology Exam 3

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CNS Effects of Muscarinic Antagonists
- drowsiness
- amnesia
Bronchial effects of muscarinic antagonsists
- bronchodilation
- decreased secretion
GI effects of muscarinit antagonists
- reduced motility & tone
- constipation
Glands effect of muscarinit antagonists

dry skin, conjunctiva and mouth
Eye effects of muscarinic antagonists
- long lasting mydriasis
- cycloplegia
- sandy eyes
- contraindicated in glaucoma
Bladder effects of muscarinic antagonists
- urinary retention
- enuresis
Clinical uses of muscarinic antagonists
- motion sickness
- dysuria/urgency
- parkinsonism
- diarrhea
- COPD if unresponsive to B2 agonists
- prevent vagal reflexes during surgery
Most common use for muscarinic antagonists
- pupil dilation in eye exams
- contraindicated in narrow angle glaucoma
Muscarinic antagonists are an antidote to

anticholinesterases and muscarinic agonists
Pralidoxime

removes inhibitors that inactivate AChE
Toxicities of muscarinic antagonists

opposite of SLUDGE
CNS Effects of muscarinic antagonist toxicities
- sedation
- amnesia
- delirium
- coma or convulsions
Contraindications of Muscarinic Antagonists
- angle-closure glaucoma
- prostatic hyperplasia
- acid-peptic disease (non-selective agents)
- M1 = stomach acid secretion
- M2 = GI movement
Atropine
- muscarinic receptor competitive antagonist
- belladonna alkaloid
Uses for atropine
- cosmetic (increase pupil size)
- medicine (decrease diarrhea)
- poison
Cardiovascular Effects of atropine
- increased HR
- increased Strength
Respiratory effects of atropine

relaxation of bronchial muscles
GI effects with atropine

decreased motility and secretions
GU effects of atropine

acts on kidney and ureters
Atropine effects in the EYE
- blocks sphincter muscle resulting in mydriasis
- weakens ciliary muscle leading to cycloplegia (loss of accomidation)
Toxic effects of atropine
- red
- hot
- dry
- mad
- blind
Scopolamine
- belladonna alkaloid
- muscarinic antagonist
- greater CNS activity
- more sedative
Use of scopolamine
- prevent and treat motion sickness
- preanesthetic (dry secretions)
Synthetic muscarinic antagonists
- propantheline
- methantheline
- tolterodine
propantheline
- synthetic muscarinic antagonist
- used for peptic ulcers
- slows gastric emptying
- decreases GI tone, motility and secretions
Methantheline
- synthetic muscarinic antagonist
- anti-saliva drug
tolterodine
- synthetic muscarinic antagonist
- some M3 selectivity
- treatment of urinary incontinece in adults
Cyclopentolate
- Antagonist
- mydriasis
- cycloplegia
Glycopyrolate
- antagonist
- preoperative med
- IBS
Tropicamide
- dilation
- mydriasis
- cycloplegia
Phenylephrine
- alpha agonist
- mydriasis without cycloplegia
- reverse with pilocarpine or alpha blocker
Ipratropium
- dry mouth
- cough
- metalic taste
- used for COPD, Asthma and Nasal rhinorrhea
Treatment of reversible AChE inhibition

Atropine
treatment of irreversible AChE inhibition
- atropine
- pralidoxime
Nicotine

stimulation and blockade of nicotinic receptors in high doses
Competitive nicotinic ganglionic antagonists
- trimethaphan
- TEA
- mecamylamine (low doses)
Non-competitive nicotinic ganglionic antagonists
- hexamethonium
- mecamylamine (high doses)
Neuromuscular junction nicotinic competitive antagonist
- tubocurarine
- blocks acces to receptor binding site
- does not cross BBB
Neuromuscular junction depolarizing agents
- succinylcholine
- vecuronium
- pancuronium
CNS effects of ganglionic blockers (nicotinic antagonists)
- sedation
- tremor
Eye effects of ganglionic blockers
- predictable cycloplegia
- unpredictable pupil effect
- predominant parasympathetic effect - dilation ?
Cardiovascular effects of nicotinic antagonist ganglionic blockers
- hypotension
- moderate tachycardia
Other effects of ganglionic blockers
- GI constipation
- urinary retention
- erection and ejaculation dysfunction
- increased response to autonomic drugs
Curare

poison which paralyzes respiratory muscles
Drugs altering the synthesis, release or degradation of ACh
- hemicholinium
- botulinium toxin
- black widow spider venom
- tetrodotoxin
- dantroline
Hemicholinium

ACh reuptake inhibitor
Botulinum toxin

prevents release of ACh by interfering with Ca²⁺ influx
Black widow spider venom (latrotoxin)

increases ACh release
Tetrodotoxin

Na⁺ Channel blocker
Dantrolene

depresses excitation contraction coupling inside muscle cells

Author

Rx2013

44049

Card Set

Pharmacology Exam 3

Description

Cholinergic Blockers and Cholinesterase regenterators

Updated

2010-10-21T21:26:04Z

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