CHAPTER 5: CHOLINERGIC ANTAGONISTS- ANTIMUSCARINIC AGENTS/DRUGS

Question 1

Cholinergic antagonists bind to

Answer 1

cholinoreceptors (muscarinic or nicotinic receptor) and prevent effects of ACh/cholinergic agonists

Question 2

Ganglionic blockers prefer

Answer 2

nicotinic receptors of sympathetic and parasympathetic ganglia

Question 3

neuromuscular blocking agents interfere with

Answer 3

transmission of efferent impulses to skeletal muscles
-mostly nicotinic antagonists

Question 4

result of PSNS blocking

Answer 4

-inc heart rate
- decrease GI activity
- dec urinary bladder tone and function
- pupil DILATION: mydriasis
- decrease gland secretions
- cycloplegia

Question 5

what is mydriasis?

Answer 5

pupil dilatiom

Question 6

what is cycloplegia?

Answer 6

paralysis of the ciliary muscle of the eye

Question 7

Antimuscarinic Agents

Answer 7

cholinergic antagonists block the muscarinic receptors and inhibit muscarinic function
- block cholinergic sympathetic neurons, innervate salivary and sweat glands
- NO SKELETAL MUSCLE JUNCTION OR GANGLIA ACTION

Question 8

antimuscarinic agent- Atropine
-affinity
-action
-duration of action

Answer 8

HIGH affinity for muscarinic receptors
- acts centrally and peripherally
- 4 HOUR duration of action (topically=days)

Question 9

Atropine- therapeutic actions

Answer 9

LOW DOSE: dec heart rate
HIGH DOSE: inc heart rate
EYES: long lasting mydriasis
SECRETIONS: xerostomia, reduce sweat secretion

Question 10

what is xerostomia?

Answer 10

reduced salivation/dry mouth

Question 11

Atropine- therapeutic uses/indications

Answer 11

-ANTIDOTE FOR CHOLINERGIC AGONISTS

optho use- for mydriasis
GI tract- antispasmodic agent relaxes GI
cardiovasc- treat bradycardia
antisecretory agent

Question 12

Atropine- adverse effects

Answer 12

dry mouth, blurred vision, tachycardia, urinary retention, constipation, confusion/delirium, exacerbate glaucoma

Question 13

what overcomes toxic effects of atropine?

Answer 13

physostigmine

Question 14

atropine overdose symptoms

Answer 14

hot as a hare: inc temp dec sweating
mad as a hatter: confusion and delirium
red as a beet: flushed face, tachycardia
dry as a bone: dec secretions, thirsty

Question 15

Antimuscarinic agent: Scopolamine
-affinity
-purpose
-duration of action

Answer 15

HIGH affinity for muscarinic receptors
- greater CNS action and LONGER duration of action than atropine

Question 16

Scopolamine- actions

Answer 16

effective on motion sickness, block short term memory, sedative at LOW DOSE

Question 17

Scopolamine- therapeutic uses/indications

Answer 17

prevent motion sickness, adjunct drug in anesthetics

Question 18

Scopolamine- adverse effects

Answer 18

dry mouth, blurred vision, tachycardia, urinary retention, constipation, confusion/delirium