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Pharmacology - Exam 2 > Cholinergics > Flashcards

Flashcards in Cholinergics Deck (44)
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1

What are the direct-acting Ach agonists?

  • Ach (not useful as a drug)
  • carbachol
  • bethanechol
  • nicotine
  • varenicline

2

What are the indirect-acting Ach agonists?

  • neostigmine
  • physostigmine
  • doenpezil
  • sarin (no therapeutic value)

3

What chemicals and enzyme synthesize Ach in cholinergic nerve terminals?

choline + acetyl-CoA

choline acetyltransferase (ChAT)

4

What enzyme rapidly breaks Ach down in the synaptic cleft?

Acetylcholinesterase

5

What are the two major types of cholinergic receptors?

nicotinic 

muscarinic

 

6

What kind of Ach receptor are all G-protein-coupled metabotropic receptors?

Muscarinic

7

What are the two types of muscarinic receptors and what do they do?

  1. Evens (M2 and M4) - inhibition of cAMP production (stimulates smooth muscle) or activation of voltage-gated K+ channels (inhibits smooth muscle)
  2. M1, M3, and M5 - activate IP3, diacylglycerol cascase to increase intracellular Ca2+ (stimulates smooth muscle)

8

What specific muscle do the M2 and M4 cAMP inhibiting receptors act on?

 contracts GI muscle

9

What specific muscle do the M2 and M4 K+ GTP receptors act on?

SA node cells (hyperpolarizes and slows HR)

10

What specific muscle does the M1, M3 and M5 receptors act on?

Ciliary muscle - increased Ca2+ contracts

11

Skeletal muscle postsynaptic receptors are what type?

Nicotinic

12

Postsynaptic autonomic ganglia and adrenal medulla receptors are what type?

nictonic

13

Presynaptic receptors in the CNS are what type?

mostly nicotinic

14

Postsynaptic receptors on parasympathetic end organs and sweat glands are what type?

muscarinic

15

What type of Ach receptor is on the postsynaptic receptors of the CNS?

Mostly muscarinic

16

What is an important effect of direct acting muscarinic agents on small blood vessels?

causes release of NO which dilates vessels and decreases BP

17

What are the direct-acting muscarinic agonists?

  • carbachol
  • bethanechol

18

what type of drug is carbachol?

direct-acting muscarnic agonist

 

*also a nicotinic agonist at high doses

19

what type of drug is bethanechol?

direct-acting muscarinic agonist

20

Which muscarnic agonists are not broken down by Achesterase?

carbachol and bethanechol

21

What are the indications for the direct-acting muscarinic agonists?

  • paralytic ileus (post-operative)
  • urinary retention
  • carbachol eyedrops in wide (open) angle glaucoma

22

What are the adverse effects of the direct-acting muscarinic agonists?

  • hypotension
  • diarrhea
  • vomiting
  • bronchial constriction
  • sweating

23

Who is contraindicated from receiving direct acting muscarinic agonists?

  • asthma
  • heart conditions
  • peptic ulcer
  • GI or urinary obstruction
  • hyperthyroidism (a fib)

24

What are the effects of the muscarinic antagonists?

  • tachycardia
  • blunted reflexes
  • mydriasis
  • inability to sweat
  • constipation
  • urinary retention
  • GI antispasmodic
  • possible hallucinations

25

What kind of drug is atropine and what does it do?

muscarinic antagonist

  • preanesthetic medication (reduce secretions, relax bronchi)
  • antispasmodic 
  • antidiarrheal

*crosses the BBB

26

What kind of drug is ipratropium and what does it do?

muscarinic antagonist

  • bronchodilation in COPD

 

*stays in lungs, limited Vd

27

What kind of receptors are nicotinic?

excitatory ligand gated ion channels

permeable to Na+ and K+

*Nicotinic neuronal also permable to Ca2+

28

What is the role of postsynaptic nicotinic receptors?

produce depolarization and excitation of neurons and skeletal muscle

29

Where does Ach bind to nicotinic receptors?

The alpha subunit

30

What is the function of presynaptic nicotinic receptors?

enhance release of many other neurotransmitters in the CNS