Autonomic: Anticholine Estrases (Parasympathomimetic)

Question 1

general mechanism of Anticholine esterases

Answer 1

inhibit choline esterase enzyme —> Accumulation of Acetylcholine

Question 2

enumerate reversible anti-choline esterases

Answer 2

• Physostigmine
• neostigmine
• Neostigmine substitutes (Edrophonium & Pyridostigmine, Ambenonium)

Question 3

Action of Physostigmine & Neostigmine can be summarised as:

Answer 3

• Physostgmine = (🤓) is CNS stimulant
• Neostigmine = (💪🏼) is a powerful Muscle Stimulant

Question 4

Compare between Source, Chemistry & distribution of Physostigmine & Neostigmine

Answer 4

• Physostigmine is Natural, Neostigmine is synthetic
• Physostigmine is Tertiary amine structure, Neostigmine is Quaternary structure
• Physostigmine Crosses BBB (avoided in parkinsonism), Neostigmine doesn’t cross BBB

Question 5

Uses of Physostigmine

Answer 5

Eyes:
* Glaucoma
* Counteract Mydratics

treatment of Atropine poisoning

Question 6

Uses of Neostigmine

Answer 6

• Glaucoma
• Paralytic ileus
• post-op urine retention
• Diagnosis & Treatment of Myasthenia gravis
• Antidote to atropine toxicity
• Antidote to neuromuscular blockers given during surgeory

Question 7

from Edrophonium & Pyrostigmine/Ambenonium, which one has longer duration & more specific in treating Myasthenia gravis

Answer 7

Pyrostigmine/Ambenonium

edrophonium for diagnosis of Mysthenia gravis

Question 8

Uses of Edrophonium

Answer 8

• Diagnosis of myasthenia gravis
• Treatment of Myasthenia crisis
• Diagnosis of cholinergic crisis
• Curare poisoning

Question 9

uses of Pyrostigmine/Ambenonium

Answer 9

treatment of Myasthenia gravis

Question 10

Use of Rivastigmine

Answer 10

treatment of Alzheimer’s

Question 11

Clinical Manifestations of Organophosphorus compounds poisoning

Answer 11

• Miosis
• Bradycardia
• Hypotension
• bronchospam
• Increase in secretion (salivary, bronchial, lacrimal, sweat)
• Skeletal muscle twitches —> prolonged depolarisation —> Paralysis
• Central inhibition
• Convulsions
• Collapse
• Coma

Question 12

Enumerte drugs used in treatment of OPC posioning

Answer 12

• Atropine
• Oximes (pralidoxime & obidoxime)
• Benzodiazepines (Diazipam)

Question 13

target end-points in Atropine therapy in treatment of OPC posioning

Answer 13

• HR less than 80 bpm
• Systolic bp more than 80 mmHg
• dry mouth & axilla (decreased sweat & salivary secretion)
• Clear chest with absence of wheeze (no bronchial secretion)
• Dilated pupils (Mydrasis)

Question 14

why do we use Oximes (pralidoxime & obidoxime) in treatment of OPC posioning

Answer 14

• reactivates choline esterase
• Restores muscle power

Question 15

when do Oximes (pralidoxime & obidoxime) become ineffective in treating OPC poisoning

Answer 15

in late cases —> Aging of choline esterase (complete irrevesible inactivation)

Question 16

why do we use Diazipam in treatment of OPC poisoning

Answer 16

to treat seizures (convulsions) caused either by OPC or by Atropine therapy