Cholinergic Antagonists Flashcards
(76 cards)
1
Q
Review: effect of cholinergic agonists - eye
A
- miosis
- accomodation
2
Q
Review: effect of cholinergic agonists - lungs
A
- bronchiolar constriction
- increased secretion
3
Q
Review: effect of cholinergic agonists - GI tract
A
- increased motility
- increased secretions
4
Q
Review: effect of cholinergic agonists - GU tract
A
- bladder emptying
5
Q
Review: effect of cholinergic agonists - CV system
A
- decreased vascular resistance
- bradycardia
6
Q
Review: effect of cholinergic agonists - sweat glands
A
- diaphoresis (sweating)
7
Q
Review: effect of cholinergic agonists - CNS
A
- stimulation
8
Q
Review: effect of cholinergic agonists - NMJ
A
- muscle contrction
9
Q
What is the response seen when a receptor binds an agonist?
A
- same as the endogenous compound for which the receptor was designated
10
Q
What is the response seen when a receptor binds an antagonist?
A
- often the opposite as the agonist
11
Q
What other names are muscarinic antagonists known as?
A
- parasympatholtyics
- antimuscarinic
12
Q
What is the effect of a muscarinic antagonist?
A
- blocks effect of parasympathetic autonomic dischange
13
Q
What are examples of muscarinic antagonists?
A
- atropine, scopolamine
14
Q
What is the effect of nicotinic antagonists in the ANS and NMJ?
A
- ganglionic blockers (ANS)
- neuromuscular blockers (NMJ)
15
Q
What is the effect of atropine on the eye?
A
- mydriasis (pupil dilation), opposite of miosis
16
Q
What is the action of atropine?
A
- reversibly blocks muscarinic receptors
17
Q
What is the mechanism of atropine’s action?
A
- prevents ACh from binding to muscarinic receptors
18
Q
T/F: Atropine typically blocks actions of endogenous acetylcholine better than it blocks exogenously administered cholinergics.
A
False, exogenous > endogenous
19
Q
What are the most sensitive areas to atropine?
A
- salivary
- bronchial
- sweat glands
20
Q
What are the effects of anticholinergics on the CNS?
A
- atropine has minimal effect/use
- scopolamine can produce drowsiness and amnesia which is useful as an antiemetic
21
Q
What can scopolamine toxicity in the CNS cause?
A
- CNS excitement
- agitation
- hallucinations
- coma
22
Q
What are the clinical uses & drugs of anticholinergics on the CNS?
A
- adjuncts to treat Parkinson’s tremors (Benxtropine)
- prevention of motion sickness (scopolamine injx, oral, or patch)
23
Q
What are the effects of anticholinergics on the eye?
A
- block cholinergic stimulation of pupillary constrictor muscles, result in unopposed sympathetic dilation (mydriasis)
- prevents contraction of ciliary muscle, results in loss of accommodation (cycloplegia)
- decreases lacrimal secretions (dry eyes)
24
Q
What is a contraindication of anticholinergic use and why?
A
- glaucoma
- decreases outflow of aqueous humor
25
What clinical use do anticholinergics have?
- mydriasis and cycloplegia are useful to ophthos to view retina
26
What are the effects of low dose antimuscarinics on the CV system?
- blocks M1 receptors only: bradycardia
| - because ACh still binds to M3 on sinus node that results in slowed HR
27
What are the effects of moderate to high doses of antimuscarinics on the CV system?
- blocks M1 & M2: tachycardia 2ndary to blockade of vagal slowing
- inhibiting the brakes on HR
28
What is a clinical use of moderate to high doses of antimuscarinics on the CV system?
- tx bradycardia in ACLS
| - atropine
29
What are the effects of toxic doses of antimuscarinics on the CV system?
- intraventricular conduction block (cessation of HR)
| - little effect on BP
30
What are the effects of anticholinergics on the respiratory system?
- bronchodilation
| - reduce/dry up secretions
31
What are the therapeutic uses and drugs of anticholinergics on the respiratory system?
- asthma/COPD (ipatropium, titropium)
| - prior to surgery or in vented patients (atropine, scopolamine)
32
What are the effects of antimuscarinics on the GI tract?
- decrease motility via decrease GI smooth M. contraction
| - decrease salivary and GI secretions (xerostomia)
33
What are the therapeutic uses of antimuscarinics on the GI tract?
- tx: diarrhea (atropine, inotecan) via decrease GI secretions
34
T/F: Antimuscarinics do not affect acid secretions in the stomach.
- True
35
T/F: Anticolinergic agents cannot cause significant constipation.
- False
36
What is the effect of antimuscarinics on the GU tract?
- relaxation of bladder smooth muscle, leads to reduced voiding
37
What group of patients can atnimuscarinics worsen urinary retention in?
- men with BPH (benign prostatic hyperplasia)
38
What are the clinical indications of antimuscarinics in treating urinary disorders?
- tx: urinary spasms (oxybutinin, a selective M3 antagonist)
39
What is an effective treatment for muscarinic toxicity?
- atropine
40
What is the treatment for rapid onset mushroom poisoning?
- atropine
41
What is the treatment for delayed onset mushroom poisoning?
- supportive care
| - atropine ineffective
42
What is a treatment for hyperhidrosis?
- anticholinergics
43
T/F: anticholinergics are always effective on sweat glands.
- False, different types of sweat glands
| - eccrine > apocrine
44
What are the adverse effects of anticholinergics?
- dry mouth (dry as a bone)
- mydriasis (blind as a bat)
- tachycardia
- hot, flushed skin (red as a beet)
- agitation (mad as a hatter)
- urinary retention (can't pee)
- visual changes (can't see)
- dry mouth (can't spit)
- constipation (can't shit)
45
What are the contraindications of anticholinergic use?
- glaucoma
- BPH
- gastric ulcers (due to slowed gastric emptying)
46
What happens during presynaptic inhibition of cholinergic actions?
- presynaptic proteins block the release of ACh
47
What is the result of presynaptic inhibition of cholinergic actions?
- paralysis of skeletal m.
- decreased activity at parasympathetic and sympathetic synapses
- inhibition lasts weeks to months
48
What are the drugs used for presynaptic inhibition of cholinergic actions?
- Clostridum botulinum: onabotulinum, abobotulinum, rimabotulinum
49
What is the MOA of ganglionic blocking agents?
- block ACh and its agonists at nicotinic receptors of para and sympathetic ganglia
50
What are ganglionic blocking agents also known as?
- nondepolarizing competitive antagonists
51
What is the overall result of ganglionic blocking agents?
- blocking all autonomic outflow
| - mixed sympathetic and para effects
52
What are the effects of ganglionic blockers at the CNS?
- sedation
- tremor
- choreiform (abnormal) movements
- mental aberrations
53
What are the effects of ganglionic blockers at the eye?
- cycloplegia
- loss of accommodation
- moderate dilation of pupil
54
What are the effects of ganglionic blockers at the CV system?
- tachycardia
55
What are the effects of ganglionic blockers at the GI tract?
- decreased secretions
| - decreased motility
56
What is the major use of therapeutic ganglionic blockers?
- pharmacological research
57
What is the action of neuromuscular blockers?
- block transmission b/t neuron and nicotinic receptor on skeletal m.
58
What are the two groups of neuromuscular blockers?
- nondepolarizing (antagonists)
| - depolarizing (agonists)
59
Describe the action of nondepolarizing neuromuscular blockers
- block ACh from binding nicotinic receptors
- competitive binding
- prevents depolarization of muscle fibers and inhibits contraction
60
What is the result of a nondepolarizing neuromuscular blockers?
- very relaxed/paralyzed muscle
61
What can terminate the action of nondepolarizing neuromuscular blockers?
- AChE inhibitors (neostigmine)
62
What is the clinical use of nondepolarizing neuromuscular blockers?
- adjuncts to anesthesia to produce muscle paralysis/relaxation
63
What are the groups of nondepolarizing neuromuscular blockers drugs?
suffixes:
- curarine
- curium
- curonium
64
How do the different nondepolarizing neuromuscular blockers drugs differ?
- onset of action
- 1/2 life
- means of elimination
65
Describe the action of depolarizing neuromuscular blockers
- binds to nicotinic receptors on skeletal m. and acts like ACh
66
What is the initial effect of depolarizing neuromuscular blockers?
- facilitates muscle contraction
67
What is the effect of prolonged depolarizing neuromuscular blockers?
- muscle paralysis
68
What is a drug used as a depolarizing neuromuscular blockers?
- succinylcholine
69
What are the clinical uses of depolarizing neuromuscular blockers?
- facilitate intubation
| - during electroconvulsive shock therapty
70
Give some therapeutic uses of anticholinergics
- diarrhea
- bradycardia
- asthma/COPD
71
depolarizing or nondepolarizing neuromuscular blocker: tubocurarine
- non
72
depolarizing or nondepolarizing neuromuscular blocker: atracurium
- non
73
depolarizing or nondepolarizing neuromuscular blocker: succinylcholine
- depolarizing
74
depolarizing or nondepolarizing neuromuscular blocker: rocuronium
- non
75
depolarizing or nondepolarizing neuromuscular blocker: doxacurium
- non
76
depolarizing or nondepolarizing neuromuscular blocker: vecuronium
- non
