B - 3. Cholinomimetics

Question 1

Direct acting muscarinic agonists function

Answer 1

Mimic effect of ACh on effector cells

Question 2

Direct acting muscarinic agonists names

Answer 2

carbachol (cholinester)

pilocarpine (alkaloid)

Question 3

carbachol, indication and SE

Answer 3

Smooth muscle constrictor used systemically
Used in polyneuropathy in DM?
Both M and N actions

SE: spasm, miosis, excessive secretion due to contraction of SmM (sweating, gastric secretions)
- contraindicated in peptic ulcer patients

Question 4

pilocarpine, indication, use in screening

Answer 4

Used topically for glaucgoma and dry mouth

Can be used as screening test for cystic fibrosis
- increases sweating -> measure amount of Cl- in sweat to check for CFTR mutation

Question 5

Indirect acting cholinomimetics (cholinesterase inhibitors) mechanism

Answer 5

Inhibit ACh-esterase -> increased ACh in synapse -> increased activation of muscarinic and nicotinic receptors

Does not stimulate blood vessels (blood vessel muscarinic receptors are not innervated?)

Used to reverse receptor blockage by antagonists

Question 6

Indirect acting cholinomimetics (cholinesterase inhibitors)

Answer 6

neostigmine
pyridostigmine
rivastigmine
edrophonium

Question 7

neostigmine and pyridostigmine length of action

Answer 7

Long acting
Neostigmine - 0,5 - 2 h
Pyridostigmine - 3 - 6 h

Question 8

neostigmine and pyridostigmine indications

Answer 8

Myasthenia gravis
Ileus (lack of intestinal movement)
Urinary retention

Reversal of neuromuscular blockers; “curare”

pyridostigmine is used in military as nerve gas antidote

Question 9

rivastigmine

Answer 9

Drug used in Alzheimers

SE: nausea, vomiting, weight loss

Question 10

edrophonium

Answer 10

Used in myasthenia gravis
Reversible

SE:

Question 11

myasthenia gravis (short)

Answer 11

Body produces antibodies that block, inhibit or destroy NICOTINIC acetylcholine receptors in the body