Direct Acting Cholinergic Agonists

Question 1

Cholinomimetics

Answer 1

Substances minic the effets of parasympathetic

Activate cholinergic receptors

Question 2

Direct acting vs. indirect acting cholinergics

Answer 2

Direct - bind to and directly activate musarinic and nicotinic receptors

Indirect - inhibit Achesterases and increase levels of Ach (if synapses active)

Question 3

Esters list and basic

Answer 3

Include Ach, methacholin, carbachol, and bethanechol

All are permanently charged quaternary amines

Insoluble in lipids

Question 4

Aklaloids list and basic

Answer 4

Muscarine
Pilocarpine
Nicotine

Tertiary amines (except muscarine)

Question 5

More about esters

Answer 5

Poorly absorbed and distrubuted in CNS because charged

Hydrolyzed in GI and do not cross membrane well…use SC

Susceptible to hydrolysis by cholinesterase in body (bethanechol and carbachol are least)

Vary in affinity for musc vs. nicotinic (methacholine and bathanechol have no nicotinic activity)

Question 6

Alkaloids more

Answer 6

Well absorbed for most excpet muscarine in GI

Excreted by kidneys

Nicotine poisoning

Question 7

Ach

Answer 7

No therapeutic values
Not specific
Readily hydrolized
Would activie both para and sympathetic

Question 8

Bethanecol metab and target

Answer 8

Selective for muscarinic involved in GI and bladder control

Specific

Not readily hydrolyzed

Question 9

Side effects and use of bethanecol

Answer 9

Promotes GI and bladder motility in atony or neurogenic bladder/paralytic ileus or Gastric reflux

Sweating, urinary/diarrhea, decreased BP and HR, bronchoconstriction and spasms (asthma patients), sialogogue and lacrimation

Does not cross BBB

Question 10

Methacholine

Answer 10

More specific for muscarinic

Less hydrolyzed by AChE

Mused as a test in patients with normal spirometric reading but comlain of chest tightness and difficulty breathing

Question 11

Carbachol

Answer 11

Selective for nicotinic but still have activity at muscarinic

Not hydrolyzed

Promotes miosis of iris (constriction) prior to ocular surgery

Open angle glaucoma

Topical

Question 12

First line against glaucoma

Answer 12

Alpha 2 agonists like apraclonidine or beta antagonists like timolol because they reduce aqueous humor production

Question 13

Pilocarpine

Answer 13

Glaucoma (close angle) and xerostomia

Not hydrolyzed by AChE

Specific for muscarinic

Causes miosis and decreases intra-ocular pressure…can blur vision

Corsses BBB

Question 14

Cevimeline

Answer 14

Tx in xerostomia in case of Sjogren’s dz or in patients undergoing antineoplastic tx or neck radiation

Muscarinic at M1 and M3

Cheaper than pilocarpine

Question 15

Eye cholinergic effects

Answer 15

Sphincter contraction of iris (misosi) and ciliary contraction for near vision

Question 16

heart cholinergic effects

Answer 16

SA node - decreased rate

Atria - decreased strenght

AV - increase in refractory period

Question 17

Blood vessels cholinergic

Answer 17

Artery and veins dilate because of NO production

Question 18

Lung cholienrgic

Answer 18

Bronchial smooth muscle contraction and bronchial gland stimulation

Question 19

GI tract cholinergic

Answer 19

Motility increased
Sphincters relaxed
Secretion increased

Question 20

Bladder cohlinergic

Answer 20

Detrusor contracts and sphincter relaxes

Question 21

Glands cholinergic

Answer 21

Secretin

Question 22

Indications for use of 
Carbachol
Pilocarpine
Bethanecol
Methcholine
Cevimeline

Answer 22

Glaucoma - carb and pilo
Post op GI atony - bethane
Neurogenic bladder- bethane
Dry mouth - cevimeline
Bronchoprovocation challenge - mathacholine