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Pharm II Exam 4 > Motility Disorders > Flashcards

Flashcards in Motility Disorders Deck (37):
1

What are prokinetic agents?

Drugs that selectively stimulate gut motor fxn

2

What is the action of intrinsic primary afferent neurons (IPANs)?

Activate enteric neurons responsible for peristalsis & secretory reflex

3

What action enhances the release of Ach & calcitoningene-related peptide, promoting reflex activity?

Stimulation of 5-HT4 receptors on presynaptic terminals of IPANs

4

What are cholinomimetic agents used for?

GERD
Impaired gastric emptying
Nonulcer dyspepsia
Prevention of vomiting

5

What cholinoimetic agent is NOT approved by FDA or available in the US?

Domperidone (pospartum lactation stimulation)

6

What are ADEs of metoclopramide?

Extrapyramidal effects
Tardive dyskinesia
Elevated prolactin

7

What is the MOA of erythromycin (a macrolide)?

Stimulate motilin receptors

8

How do you treat a patient w/ constipation who has no underlying dx?

Symptomatic therapy

9

List the laxative agents (8)

Bulk forming
Stool surfactant (softeners)
Osmotic
Stimulant
Chloride channel activator
Guanylate cyclase c activator
Opioid receptor antagonists
Serotonin 5-HT4 agonists

10

What 3 agents result in soft or semifluid stool in 6-12 hrs?

Bisacodyl (oral)
Senna
Mg sulfate (low dose)

11

What 6 agents cause watery evacuation in 1-6 hrs?

Mg citrate
Mg hydroxide
Mg sulfate (high dose)
Na phosphates
Bisacodyl (rectal)
PEG

12

What are 2 common preparations of bulk forming laxatives?

Natural plant products:

Psyllium
Methylcellulose

13

What is an example of a stool surfactant agent?

Docusate (oral or enema)

14

What can mineral oil cause?

Aspiration --> severe lipid pneumonitis

15

What are examples of osmotic laxatives?

Mg hydroxide (Milk of Mag)

Sorbitol & lactulose

16

What is the MOA of stimulant laxatives?

Direct stimulation of the enteric NS

17

Cathartics may be required on a _______

long-term basis

18

What are examples of stimulant laxatives?

Anthraquinone derivatives: aloe, senna, cascara

Diphenylmethane derivative:
bisacodyl

19

What are characteristics of bisacodyl (a diphenylmethane derivative)?

Minimal systemic absorption

Appears to be safe for acute & long-term use

20

What are 3 examples of opioid receptor antagonists?

Methylnaltrexone

Alvimopan

Naloxegol

21

What are clinical controversies?

1. Withholding food is considered inappropriate in pts w/ no signs of severe dehydration

2. In osmotic diarrhea, food may control the problem

3. If the mechanism is secretory, diarrhea persists

22

What are examples of antidiarrheal agents?

Opioid agonists:
loperamide, diphenoxylate

Bile salt-binding resins (cholestyramine, colestipol, colesevelam)

23

Colesevelam does not appear to have significant effects on...

absorption of other drugs

24

Describe somatostatin

Antisecretory: octreotide

14-amino-acid peptide released in the GI tract & pancreas from paracrine cells, D cells, enteric nerves, & the hypothalamus

25

What is the MOA of somatostatin?

Inhibits the secretion of numerous hormones & transmitters

Reduces intestinal fluid secretion & pancreatic secretion

Slows GI motility & inhibits gallbladder contraction

26

What do GI neuroendocrine tumors cause?

What inhibits this?

Secretory diarrhea

Antisecretory: octreotide

27

What are ADEs of octreotide?

Steatorrhea

Nausea, abd pain, flatulence, diarrhea

Prolonged tx --> hypothyroidism

Brady

28

What is the MOA of metoclopramide?

D2 receptor antagonist

Blocks D2 receptors in the trigger zone of the medulla

29

What is the action of metaclopramide?

Increases:
- esophageal peristalsis
- LES pressure
- gastric emptying

30

What is the MOA of bethanechol (a cholinomimetic)?

Stimulates M3 receptors at myenteric plexus synapses

31

What is the MOA of neostigmine (a cholinoimetic)?

Acetylcholinesterase inhibitor

32

What are ADEs of cholinomimetics?

Salivation, N/V/D, brady

33

Which types of laxative cause softening of feces in 1-3 days?

Bulk-forming
Emollients (softeners)
PEG

34

What are 2 examples of purgatives (laxatives)?

Mg citrate & Na phosphate

35

What are ADEs of anthraquinone derivatives: aloe, senna, & cascara?

Melanosis coli

Concern that these agents may be carcinogenic, but studies do not suggest relation

36

What is alvimopan (an opioid receptor antagonist) used for?

shortens the period of postop ileus in hospitalized pts who undergo small or large bowel resection

37

What are 3 adsorbents?

Kaolin-pectin

Polycarbophil

Attapulgite