Parasympathetic Agonists

Question 1

What type of inhibitor is ACh esterase?

Answer 1

Indirect

ACh esterase inhibitors can be reversible or irreversible.

Question 2

What is the absorption characteristic of tertiary amines?

Answer 2

Good absorption

Tertiary amines are often well absorbed in the body.

Question 3

Which amine does not pass the blood-brain barrier?

Answer 3

Quaternary amine

Quaternary amines have poor absorption and do not cross the BBB.

Question 4

What are the uses of Physostigmine?

Answer 4

• Glaucoma
• Counteract a Mydriatic
• Atropine poisoning

Physostigmine is less toxic than neostigmine.

Question 5

What are the side effects of ACh esterase inhibitors?

Answer 5

• CNS convulsions
• Diarrhea
• Urination
• Miosis
• Bradycardia
• Bronchospasm
• Excitation of muscle
• Lacrimation
• Salivation
• Sweating

This collection of symptoms is often summarized as DUMBBELSS.

Question 6

What is the primary use of Neostigmine?

Answer 6

Myasthenia gravis

Neostigmine is a direct skeletal muscle stimulant.

Question 7

How does Neostigmine compare in toxicity to Physostigmine?

Answer 7

More toxic than physostigmine

Neostigmine requires atropine for management of toxicity.

Question 8

What is the duration of action of Pyridostigmine compared to Neostigmine?

Answer 8

Longer action duration than neostigmine

Pyridostigmine has less side effects than neostigmine.

Question 9

What is the primary use of Edrophonium?

Answer 9

• Diagnose myasthenia Gravis
• Terminate paroxysmal supraventricular tachycardia attacks

Edrophonium has a rapid onset and short duration.

Question 10

Which drugs are used to treat or slow the progression of Alzheimer’s?

Answer 10

• Tacrine
• Rivastigmine
• Donepezil

Tacrine may cause hepatotoxicity.

Question 11

What happens after the aging of organophosphorus compounds?

Answer 11

New enzyme requires synthesis

Organophosphorus compounds phosphorylate AChE.

Question 12

What is the key characteristic of the kinetics of neostigmine?

Answer 12

Doesn’t pass BBB

Neostigmine has bad distribution and primarily acts on GIT and urinary bladder.

Question 13

What is the primary action of ACh esterase inhibitors?

Answer 13

CNS stimulant

These inhibitors are often used in various medical conditions.

Question 14

Fill in the blank: Physostigmine is used to counteract _______.

Answer 14

Atropine poisoning

Physostigmine can also be used for glaucoma.

Question 16

What is the action duration of ACh?

Answer 16

Brief action duration due to rapid hydrolysis

Question 17

What type of receptors does ACh act on?

Answer 17

Muscarinic (M) and Nicotinic (N) receptors

Question 18

Why is ACh ineffective when taken orally?

Answer 18

It is a quaternary amine

Question 19

What is the effect of ACh on contractility?

Answer 19

Negative inotropic effect

Question 20

What is the effect of ACh on heart rate?

Answer 20

Negative chronotropic effect

Question 21

What is the effect of ACh on conductivity?

Answer 21

Negative dromotropic effect

Question 22

What vascular effect does ACh have?

Answer 22

Vasodilation

Question 23

What is the percentage of vasodilation caused by ACh?

Answer 23

32%

Question 24

What effect does ACh have on the gastrointestinal tract?

Answer 24

Increases motility

Question 25

What happens to sphincters when ACh is released?

Answer 25

Relaxation of sphincters

Question 26

What is the effect of ACh on secretion?

Answer 26

Increases secretion

Question 27

What muscle does ACh contract for urination?

Answer 27

Detrusor muscles

Question 28

What is the effect of ACh on bronchial smooth muscle?

Answer 28

Bronchoconstriction

Question 29

What effect does ACh have on eye muscles?

Answer 29

Contraction of radial and ciliary muscles

Question 30

What is the result of ciliary muscle contraction?

Answer 30

Near vision accommodation

Question 31

What is the effect of ACh on intraocular pressure?

Answer 31

Decreases intraocular pressure

Question 32

What secretions increase due to ACh?

Answer 32

Sweat, saliva, and lachrymal secretion

Question 33

What type of ganglia does ACh affect?

Answer 33

Autonomic ganglia

Question 34

What gland is stimulated by ACh?

Answer 34

Adrenal gland

Question 35

What is the effect of ACh at the myoneural junction?

Answer 35

Stimulates muscle contraction

Question 36

What happens to blood pressure with ACh release?

Answer 36

Rise in blood pressure

Question 37

What is released from the adrenal gland due to ACh?

Answer 37

Epinephrine (EP)

Question 38

What is the paradoxical effect of ACh?

Answer 38

Peripheral vasoconstriction

Question 39

What happens to skeletal muscles at small doses of ACh?

Answer 39

Contraction of skeletal muscles

Question 40

What is the effect of large doses of ACh?

Answer 40

Initial contraction followed by flaccid paralysis

Question 41

What type of paralysis occurs with large doses of ACh?

Answer 41

Flaccid paralysis due to depolarization