Pharm 4 Lecture

Question 1

What is the site of action of ganglionic blockers?

Answer 1

Nicotinic receptors at the ganglia

Question 2

Names for Anticholinergics

Answer 2

Cholinergic Antagonist
Cholinoreceptor-Blocking Agents
Parasympatholytics
Vagolytics

Question 3

3 Categories of of Anticholinergics

Answer 3

1. Antimuscarinics
2. Ganglionic Blockers
3. Neuromuscular Blockers

Question 4

Antimuscarinics

Answer 4

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

Question 5

Ganglionic Blockers

Answer 5

Trimethophan (Arfonad)

Question 6

Neuromuscular Blockers: Non-Depolarizing

Answer 6

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)

Question 7

Neuromuscular Blockers: Depolarizing

Answer 7

Act as agonists

Succinylcholine (Anectine)

Question 8

Anesthetic Adjuncts

Answer 8

Neuromuscular Blockers

Question 9

Atropine

Answer 9

Typical adult dose: 0.4-1.0 mg

For bradycardia, repeat q3-5 min up to 3x

Question 10

Robinul

Answer 10

Typical adult dose

0.2-0.6 mg

Question 11

How do we use antimuscarinics?

Answer 11

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

Question 12

What are the side effects of antimuscarinics?

Answer 12

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

Question 13

What are the uses for ganglionic blockers?

Answer 13

Rarely used

Hypertensive crises, dissecting aortic aneurysms, reduce bleeding during neurosurgery

Question 14

Ganglionic Blocker Side Effects

Answer 14

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

Question 15

Trimethophan (Arfonad)

Answer 15

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

Typical adult dose:

1. 0-3.0 mg bolus
2. 5-6.0 mg/min

Question 16

What is neuromuscular blocker agent used for?

Answer 16

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

Ex. Curare
Tubocurare developed clinically (paralyze diaphragm)

Question 17

What are nondepolarizing neuromuscular blockers antagonized by?

Answer 17

AChE inhibitors

Question 18

What are nondepolarizing neuromuscular blockers synergistic with?

Answer 18

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

Question 19

Anectine

Answer 19

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

Question 20

Sux Metabolism

Answer 20

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

Question 21

Sux Side Effects

Answer 21

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)