L 18 Flashcards Preview

Pharmacology Fall 2015 > L 18 > Flashcards

Flashcards in L 18 Deck (25):
1

Name the M3 specific antagonists

Tolterodine
Solifenacin

2

Belladonna plant think:

Atropine
Scopolamine

3

Differences between atropine and scopolamine

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

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

4

What M antagonist is used to dilate the eye?

Tropicamide

5

Ipratropium

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

6

Tropicamide

M Antagonist
Used to dilate the eye

7

What is used with atropine to prevent diarrhea?

Diphenoxylate (Lomotil)

8

Drugs used after prostate surgery

Oxybutinin
Trospium
To prevent bladder spasm

9

Dose dependence of atropine

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

10

Atropine

M antagonist
No CNS

11

Scopolamine

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

12

Role of M antagonists in Parkinson's

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

13

Effects of anticholinergic M antagonists on the eye

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.

14

M antagonists used for eye dilation

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

15

Cholinergic antagonist effects on heart

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

16

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

Atropine helps by decreasing vagal tone and increasing AV conduction

17

M antagonist effects on lungs

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

18

Drug used to prevent cardiac vagal response when handling organs

Glycopyrrolate

19

Dicyclomine

M antagonist
prevents GI spasms

20

Ipratropium

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

21

Tolterodine

M3 antagonist
For bladder overactivity
Low lipid solubility
Low CNS

22

Oxybutynin

M antagonist
Prevents bladder spasm after prostate surgery

23

Glycopyrrolate

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

24

Contraindications for antimuscarinic drugs

Uncontrolled or narrow-angle Glaucoma
Males with BPH because would cause urinary retention

25

Treatment of mushroom overdose or organophosphate poisoning

IV atropine until mouth dry and mydriasis occurs