Autonomic Cholinergic Pharmacology

Question 1

Where does acetylcholine act?

Answer 1

autonomic ganglia, parasympathetic neuroeffector junctions, somatic neuromuscular junctions, adrenal medulla, and central nervous system

Question 2

What are cholinergic or cholinomimetic drugs?

Answer 2

drugs that produce ACh-like effects

Question 3

What are direct-acting cholinergic or choliinomimetic drugs?

Answer 3

agonists at the muscarinic ACh receptors

Question 4

What are cholinesterase inhibitors?

Answer 4

blockers of the acetylcholinesterases that degrade endogenous ACh

Question 5

What are parasympatholytic drugs?

Answer 5

drugs that block or inhibit ACh-like effects at parasympathetic neuroeffector nunctions (mAChR antagonists)

Question 6

Generally, how do cholinergic receptor agonists act on the heart?

Answer 6

they are inhibitory - decrease SA rate, decrease contractile strength of the atria, decrease conduction velocity of the AV node

Question 7

How do cholinergic receptor agonists act on the lungs?

Answer 7

contraction of the bronchial muscle and stimulation of the bronchial glands

Question 8

How do cholinergic receptor agonists work on the gastrointestinal tract?

Answer 8

increased motility

Question 9

How do cholinergic receptor agonists act on the bladder?

Answer 9

detrussor contraction and trigone/spinchter relaxation (peeing)

Question 10

How do cholinergic receptor agonists act on the glands?

Answer 10

secretion

Question 11

What muscarinic receptors primarily mediate the gastrointestinal tract?

Answer 11

M1 receptors

Question 12

What muscarinic receptors primarily mediate the cardiovascular system?

Answer 12

M2 receptors

Question 13

What muscarinic receptors primarily mediate everything else (urinary bladder, the eye)?

Answer 13

M3 receptors

Question 14

What are cholinomimetic alkaloids?

Answer 14

naturally occurring alkaloids that act like acetylcholine

Question 15

What are the cholinomimetic alkaloids that we discussed in class?

Answer 15

pilocarpine, arecoline, muscarine

Question 16

What choline esters were discussed in class?

Answer 16

acetylcholine, methacholine, carbachol, and bethanechol

Question 17

What is bethanecol used for?

Answer 17

stimulating GI motility in horses with ileus and stimulating the urinary bladder

Question 18

What is pilocarpine used to treat?

Answer 18

glaucoma and KCS

Question 19

How does pilocarpine treat glaucoma?

Answer 19

Direct stimulation of the muscarinic receptors on the pupil to constrict it, change the geometry of the eye, and promote aqueous humor flow

Question 20

How does polocarpine treat KCS (dry eye)?

Answer 20

it stimulates the muscarinic receptors on the lacrimal gland which will thus stimulate tear production

Question 21

What are the adverse effects of parasympathomimetics?

Answer 21

Slowing of heart rate and AV block, increased airway resistance (dyspnea), hypotension, and SLUD syndrome

Question 22

What does ‘SLUD’ stand for?

Answer 22

salivation, lacrimation, urination, and defecation

Question 23

What happens with using higher concentrations of carbachol or other muscarinic targeted drugs?

Answer 23

There are nicotinic effects - stimulation of sympathetic ganglia, catecholamine release from the adrenal gland, skeletal muscle fasiculations

Question 24

What does acetylcholinesterase do?

Answer 24

terminates the action of endogenous ACh at just about every site where ACh is released

Question 25

What reversible cholinesterase inhibitors did we discuss in class?

Answer 25

physostigmine, neostigmine, edrophonium, pyridostigmine

Question 26

What is edrophonium used for?

Answer 26

the diagnosis of myasthenia gravis

Question 27

What is pyridostigmine used for?

Answer 27

for treatment of myasthenia gravis

Question 28

What are the irreversible cholinesterase inhibitors that we discussed in class?

Answer 28

Organophosphates - malathion, parathion, dichlorvos, sarin, tabun, and soman (nerve gas)

Question 29

What does mild exposure to organophosphate toxicity cause?

Answer 29

pupillary constriction, tightness in the chest, watery discharge from the nose, wheezing

Question 30

What does severe exposure to organophosphate toxicity cause?

Answer 30

DUMBLES - diarrhea, urination, miosis, bronchoconstriction, excitation of skeletal muscle, lacrimation, and salivation and sweating

Question 31

What type of drugs are atropine and glycopyrrolate?

Answer 31

They are muscarinic receptor antagonists

Question 32

What are the physiological effects of atropine?

Answer 32

tachycardia, relaxes the gastrointestinal system and decreases secretion, bronchodilation and decreased secretion, and dry oral mucosa