L 18

Question 1

Name the M3 specific antagonists

Answer 1

Tolterodine

Solifenacin

Question 2

Belladonna plant think:

Answer 2

Atropine

Scopolamine

Question 3

Differences between atropine and scopolamine

Answer 3

Atropine: no CNS, effects are peripheral, CNS effects only at high doses

Scopolamine: Quick CNS penetration=> sedation, amnesia, euphoria,

Question 4

What M antagonist is used to dilate the eye?

Answer 4

Tropicamide

Question 5

Ipratropium

Answer 5

M Antagonist
No CNS, poor oral absorption
Inhaled to treat COPD

Question 6

Tropicamide

Answer 6

M Antagonist

Used to dilate the eye

Question 7

What is used with atropine to prevent diarrhea?

Answer 7

Diphenoxylate (Lomotil)

Question 8

Drugs used after prostate surgery

Answer 8

Oxybutinin
Trospium
To prevent bladder spasm

Question 9

Dose dependence of atropine

Answer 9

Blocking M receptors has most effect on tissues where there is high PS tone. From low to high dose, will affect:
Glands=> dec sweat and salivation
Heart=> tachycardia
Eyes=> blurred vision
GI/GU=> bowel problems, bladder problems
Brain=> ataxia, hallucinations, delerium, coma

Question 10

Atropine

Answer 10

M antagonist

No CNS

Question 11

Scopolamine

Answer 11

Quick CNS access
Causes sedation, amnesia
Treats nystagmus and motion sickness

Question 12

Role of M antagonists in Parkinson’s

Answer 12

In parkinson’s disease and with antipsychotic drugs, Dopamine is blocked or reduced. M antagonists block Ach to help restore balance between the two chemicals in the corpus striatum.
Benztropine is commonly used

Question 13

Effects of anticholinergic M antagonists on the eye

Answer 13

Blocking M receptors blocks sphincter pupillae and the ciliary muscle causing mydriasis and cycloplegia.
Pupil dilation blocks flow of humor causing increase in intraocular pressure.

Question 14

M antagonists used for eye dilation

Answer 14

Tropicamide
Homatropine
Both short-acting
Also cause increase intraocular pressure
Only used in open-angle glaucoma that is well managed

Question 15

Cholinergic antagonist effects on heart

Answer 15

Low dose of Atropine causes bradycardia by inhibiting presynaptic M2=> inc Ach release

Mod dose of Atropine causes tachycardia because of dec M2 action on SA node and:
Decreased M2 inhibition on symp nerve=> inc NE release

Larger effect on young adults with lots of Vagal tone, less effect on babies and elderly with lower Vagal tone

Blocking vagal tone => inc AV conduction which can cause arrhythmias

Question 16

To overcome an AV heart block, what can be given?

Answer 16

Atropine helps by decreasing vagal tone and increasing AV conduction

Question 17

M antagonist effects on lungs

Answer 17

Blocks M3=> bronchodilation
Helpful in acute asthma, but not chronic
Drugs of choice for COPD

Question 18

Drug used to prevent cardiac vagal response when handling organs

Answer 18

Glycopyrrolate

Question 19

Dicyclomine

Answer 19

M antagonist

prevents GI spasms

Question 20

Ipratropium

Answer 20

M antagonist
used for acute asthma or COPD
Not absorbed well, effects remain localized to lung

Question 21

Tolterodine

Answer 21

M3 antagonist
For bladder overactivity
Low lipid solubility
Low CNS

Question 22

Oxybutynin

Answer 22

M antagonist

Prevents bladder spasm after prostate surgery

Question 23

Glycopyrrolate

Answer 23

M antagonist
Useful for heart
Also useful to decrease GI symptoms when using Neostigmine for Myasthenia Gravis

Question 24

Contraindications for antimuscarinic drugs

Answer 24

Uncontrolled or narrow-angle Glaucoma

Males with BPH because would cause urinary retention

Question 25

Treatment of mushroom overdose or organophosphate poisoning

Answer 25

IV atropine until mouth dry and mydriasis occurs