PHRM 825: Anticholinergics

Question 1

Anticholinergics bind to the receptor and disrupt binding of what molecule?

Answer 1

Acetylcholine

Question 2

What are muscarinic receptors?

Answer 2

Acetylcholine regulated G protein-coupled receptors

Question 3

What are anticholinergics also known as?

Answer 3

Antimuscarinic

Question 4

How do anticholinergics cause mydyriasis?

Answer 4

They inhibit ACh action on M3 receptor in pupillary constrictor muscle

Question 5

How do anticholinergics cause cycloplegia

Answer 5

Inhibit ACh action on M3 receptors in ciliary muscle

Question 6

What is cycloplegia?

Answer 6

Loss of focus/regulation of lens thickness in the eye

Question 7

How do anticholinergics cause incontinence?

Answer 7

Bladder relaxation via M3 receptor which mediates contraction of the bladder and M2 receptor (indirectly) inhibits relaxation

Question 8

How do anticholinergics help with irritable bowel syndrome?

Answer 8

Induce GI tract intestinal paralysis (antispasmodic agents); reduce secretions (was considered useful for ulcers)

Question 9

How/why are anticholinergics used as a pre-operative anti-secretory?

Answer 9

Used with inhalant anesthetics to reduce accumulations of secretions (salivary, mucous membranes of respiratory tract)

Question 10

How are anticholinergics used to treat COPD?

Answer 10

Reduce secretions, cause bronchial dilation (used in combination with a beta-adrenergic agonist)

Question 11

What are possible clinical uses of anticholinergics?

Answer 11

• Ocular exams
• Incontinence
• IBS
• Pre-operative anti-secretory
• COPD
• Motion sickness
• Parkinson’s disease

Question 12

What is the mechanism of antimuscarinics?

Answer 12

Competitive and reversible inhibition of muscarinic receptor activation by preventing the binding of acetylcholine

Question 13

What are the 2 categories that most antimuscarinics fall into?

Answer 13

Tertiary amines and quaternary amines

Question 14

What are tertiary amines mainly used for?

Answer 14

Ocular and CNS applications

Question 15

What are quaternary amines mainly used for?

Answer 15

GI tract and peripheral applications

Question 16

What are 2 long acting tertiary amines?

Answer 16

Atropine and scopolamine

Question 17

What are 3 short acting tertiary amines?

Answer 17

Homatropine, cyclopentolate, and tropicamide

Question 18

What tertiary amine is sued for Parkinson’s?

Answer 18

Benztropine (Cogentin)

Question 19

What quaternary amines are used for GI disorders?

Answer 19

Glycopyrrolate and propantheline bromide (probanthine)

Question 20

What quaternary amine is used to treat COPD

Answer 20

Ipratropium bromide

Question 21

What is the mnemonic device that summarizes the symptoms for atropine overdose?

Answer 21

Red as a beet, dry and a bone, blind as a bat, hot as a firestone, and mad as a hatter

Question 22

What are clinical uses for nicotinic receptor antagonists?

Answer 22

• Muscle relaxation during surgery
• Tracheal intubation
• Control of ventilation (patients with ventilatory failure)
• Treatment of convulsions

Question 23

What are the 2 modes of action for neuromuscular blockers on the nicotinic receptor?

Answer 23

Depolarizing competitive and nondepolarizing competitive

Question 24

Which neuromuscular blockers have an extremely short duration of action?

Answer 24

Depolarizing neuromuscular blocker

Question 25

Which neuromuscular blocker has a very short duration of action?

Answer 25

Succinylcholine

Question 26

Which neuromuscular blocker has a very long duration of action?

Answer 26

Pancuronium