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Flashcards in Pharm 4 Lecture Deck (21):
1

What is the site of action of ganglionic blockers?

Nicotinic receptors at the ganglia

2

Names for Anticholinergics

Cholinergic Antagonist
Cholinoreceptor-Blocking Agents
Parasympatholytics
Vagolytics

3

3 Categories of of Anticholinergics

1. Antimuscarinics
2. Ganglionic Blockers
3. Neuromuscular Blockers

4

Antimuscarinics

Atropine
Glycopyrrolate (Robinul)
Benzotropine (Cogentin)
Propantheline
Scopolamine
Many others

5

Ganglionic Blockers

Trimethophan (Arfonad)

6

Neuromuscular Blockers: Non-Depolarizing

Act as antagonists
All are given IV but vary in 1/2 life, length, metabolism and propensity to cause histamine release

Vecuronium
Cisatracurium (Nimbex)
Pancuronium (Pavulon)
Rocuronium (Zemuron)

7

Neuromuscular Blockers: Depolarizing

Act as agonists
Succinylcholine (Anectine)

8

Anesthetic Adjuncts

Neuromuscular Blockers

9

Atropine

Typical adult dose: 0.4-1.0 mg
For bradycardia, repeat q3-5 min up to 3x

10

Robinul

Typical adult dose
0.2-0.6 mg

11

How do we use antimuscarinics?

Patients with advanced heart disease often have increased parasympathetic tone
Symptomatic bradycardia
PEA/Electromechanical dissociation
AV Block

Adjunct Parkinson's Disease Therapy
Motion sickness
ophthalmic examinations
Excessive GI hypermotility (Lomotil)
urinary urge incontinence

12

What are the side effects of antimuscarinics?

Dilated pupils
Hot dry skin
Confusion/Constiplation
tachycardia (knocking out vagus nerve)
dry mouth
sedation/stasis of urine
anorexia

13

What are the uses for ganglionic blockers?

Rarely used
Hypertensive crises, dissecting aortic aneurysms, reduce bleeding during neurosurgery

14

Ganglionic Blocker Side Effects

Profound hypotension via loss of sympathetic tone
Histamine release
Negative chronotrope
Negative ionotrope (no reflex tachy)
profound constipation

15

Trimethophan (Arfonad)

Ganglionic Blocker
Given IV
short duration of action (5-15 minutes)

Typical adult dose:
1.0-3.0 mg bolus
0.5-6.0 mg/min

16

What is neuromuscular blocker agent used for?

Extensively in surgery to prevent patient movement
Does not sedate, tranquilize, or anesthetize the patient

Ex. Curare
Tubocurare developed clinically (paralyze diaphragm)

17

What are nondepolarizing neuromuscular blockers antagonized by?

AChE inhibitors

18

What are nondepolarizing neuromuscular blockers synergistic with?

Calcium-channel blockers
Halogenated hydrocarbon gas anesthetics
Aminoglycoside antibiotics (amikacin, gentamycin)- inhibit ACh release

19

Anectine

"Sux"
noncompetitive agonist
Very short-acting (shorter duration of action than any nondepolarizing agent (<8min) so useful in intubation

20

Sux Metabolism

Broken down by pseudocholinesterase when circulating in the plasma (but not AChE at the NMJ)

Must diffuse away from the NMJ to be metabolized and allow ACh back into its receptors

21

Sux Side Effects

Linked to malignant hyperthermia when used with gas anesthetic Halothane (Fluothane)

Prolonged apnea in patients with genetic pseudocholinesterase deficiency

most common in persian communities and certain indian communities

Hyperkalemia (K cell pumps locked open)