Palliation of Constipation, Nausea, and Vomiting Flashcards Preview

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Flashcards in Palliation of Constipation, Nausea, and Vomiting Deck (57):
1

Bulking agent (laxatives)

Dietary Fiber/ Psyllium (Metamucil)

2

Bulking agent (Fiber/Psyllium-Metamucil) MOA

Increase stool weight, cause retention of fluid in stool, stimulate peristalsis

3

Bulking agent (Fiber/Psyllium-Metamucil) SE/Contra

SE: flatulence
CI: do not use in debilitated patients who cannot drink adequate fluid
*MUST increase fluid intake, otherwise hard massive stool

4

Osmotic laxatives- Nonabsorbable sugars

Lactulose/Sorbitol

5

Osmotic laxatives-Nonabsorbable sugars (Lactulose/Sorbitol) MOA

Draw water into the bowel lumen and into the stool; (nonabsorbable sugars)
Lactulose: bacteria degrade in colon, increases osmotic pressure and acidification of stool, increase stool water content
Sorbitol: does not need to be degraded, works more quickly

6

Osmotic laxatives-Nonabsorbable sugars (Lactulose/Sorbitol) SE

Sickly sweet, bloating, cramps, flatulence

7

Osmotic laxatives-Nonabsorbable sugars (Lactulose/Sorbitol) Indication

Treat Constipation (NOT used to prevent constipation)

8

Osmotic laxatives

Nonabsorbable sugars (Lactulose/Sorbitol)
Saline and magnesium salts (Magnesium citrate/Magnesium hydroxide-MOM/Sodium phosphate)
Polyethylene Glycol (Miralax, Glycolax/Colyte, Golytely)

9

Osmotic laxatives- Saline and magnesium salts

Magnesium citrate
Magnesium hydroxide=Milk of Magnesia
Sodium phosphate=Fleets Phospho-Soda

10

Osmotic laxatives- Saline and magnesium salts MOA

Osmotically active particles (Mg, Phos, Na)
*Mg also stimulates CCK (stimulates peristalsis)
Increased intraluminal volume
Stimulates intestinal activity
High dose: rapid bowel evacutation

11

Osmotic laxatives- Saline and magnesium salts SE/CI

CI: Bowel obstruction, Dehydration, Electrolyte abnormalities, renal failure (caution with CHF and LF)
SE: ischemic colitis, acute phosphate nephropathy (sodium phosphate)--intratubular deposition of calcium-phosphate

12

Osmotic laxatives- Saline and magnesium salts Indication

Magnesium citrate/Sodium phosphate: Bowel preps
Magnesium hydroxide-MOM: constipation

13

Osmotic laxatives-Polyethylene Glycol

Miralax, Glycolax (constipation)
Colyte, Golytely (bowel prep)

14

Osmotic laxatives-Polyethylene Glycol MOA

Osmotically active > retains water in stool > softer stool = more frequent bowel movements
Contents NOT absorbed systemically, SAFE in anyone

15

Osmotic laxatives-Polyethylene Glycol Indications

Miralax, Glycolax: constipation (small daily doses)
Colyte, Golytely: bowel prep (large volumes)

16

Stimulant Laxatives

Senna, Bisacodyl

17

Stimulant Laxatives MOA

Stimulate bowel motility

Senna: Converts to active metabolites by bacteria in colon>
Stimulates myenteric plexus > peristalsis

Bisacodyl: parasympathetic stimulation > peristalsis

18

Stimulant Laxatives SE

Cramping, Melanosis Coli (colonic lumen-macs filled with lipofusion)

19

Stimulant Laxatives Indications

Constipation (for opioids)

20

Detergent Laxatives (stool softeners)

Docusate (Colase)

21

Detergent Laxatives MOA

Lube up the bowels, makes them more slippery
Increases penetration of fluid into the stool
Emulsifies feces, water, fat

22

Lubricants

Glycerin suppository/enema
Mineral oil enema

23

Lubricant MOA

Glycerin suppository/enema:
Osmotic- softeners, lubricates stool
Irritant- stimulates rectal contractions
Mineral oil enema:
Coats fecal material
Softens stool, lubricates

24

Lubricant SE

Mineral oil should NEVER be administered oral to debilitated patients > aspiration > lipoid pneumonitis

25

Lubricant Indication

Fecal Impaction

26

Large volume enemas MOA

Soften stool by increasing water content
Distend distal colon
Induce peristalsis

27

Large volume enemas indication

Fecal impaction

28

Palliation of Constipation (steps)

Stool softener (Docusate)
Stimulant (Senna, Bisacodyl)
Osmotic agent (Lactulose, sorbitol, MOM, polyethylene glycol-low dose)
Enemas (Tap water, sodium phosphate)
Magnesium citrate/sodium phosphate (last choice)

29

Chemoreceptor Trigger Zone (stimulants, receptors)

Can be stimulated by drugs (opiates, chemo), renal failure (metabolic products), bacterial toxins
Receptors: dopamine, 5-HT3

30

Vestibular center (stimulants, receptors)

Motion sickness, inner ear infection
Receptors: acetylcholine, histamine

31

Gut (stimulants, receptors)

Gastroenteritis, radiation, GERD, metastasis, obstruction, local toxins, drugs
Receptors: 5-HT3, vagus, dopamine

32

Vomiting Center Receptors

Acetylcholine
H1
5-HT2

33

Dopamine Receptor Antagonists

Prochlorperazine
Metaclopramide

34

Prochlorperazine (Dopamine Antagonist) MOA

Central dopamine receptor antagonist in CTZ
Peripherally blocks vagus nerve (GI)

35

Prochlorperazine (Dopamine Antagonist) Indications

Opioid related nausea and vomiting
GI disorders, inflammation, infection

36

Prochlorperazine (Dopamine Antagonist) SE

Extrapyramidal effects (movement disorders)
Dystonic reactions

37

Metoclopramide (Dopamine Antagonist) indications

Chemotherapy induced nausea and vomiting
Treatment of upper GI tract dysmotility (diabetic gastroparesis, gastric stasis)

38

Metoclopramide (Dopamine Antagonist) MOA

Blocks the chemoreceptor trigger zone
Promotes motility of upper GI tract > increases gastric emptying

39

Metoclopramide (Dopamine Antagonist) SE

Extrapyramidal effects (dystonia, akathisia, parkinsonism)
Acute dystonic reactions (trismus, torticollis-jaw, neck spasm)
CAUTION: parkinson's disease

40

Ondansetron MOA

Serotonin (5-HT3) receptor antagonist

41

Ondansetron Indication

Chemotherapy induced nausea/vomiting and prophylaxis
Radiation induced nausea/vomiting and prophylaxis
Post operative N/V

42

Ondansetron SE

QT prolongation
Headache

43

Promethazine MOA

Histamine (H1) receptor antagonist

44

Promethazine Indications

Motion sickness Rx/prevention
Inner ear vestibular disorder

45

Promethazine SE

Sedation

46

Scopolamine MOA

Anticholinergic

47

Scopolamine Indication

Treatment of motion sickness
Vestibular apparatus mediated N/V

48

Scopolamine SE

Confusion
Urinary retention
Acute narrow angle glaucoma
Dry mouth

49

Corticosteroids

Prednisone
Dexamethasone

50

Corticosteroid (Prednisone, Dexamethasone) Indication

Nausea due to increased intracranial pressure

51

Benzodiazepines

Lorazepam
Diazepam

52

Benzodiazepines (Lorazepam, Diazepam) Indication

Anxiety associated nausea and vomiting (anticipatory)

53

Palliation of N/V: Vestibular (Receptors/Drugs)

Receptors: Cholinergic, Histaminic
Drugs: Scopolamine (anti-Ach); Promethazine (anti-H)

54

Palliation of N/V: Obstruction of Bowel caused by constipation (Receptors/Drugs)

Receptors: 5-HT3, Dopamine, Vagus
Drugs: Appropriate laxatives!

55

Palliation of N/V: dysMotility of upper GI tract (Receptors/Drugs)

Receptors: Dopamine
Drugs: Metoclopramide

56

Palliation of N/V: Infection, Inflammation (receptors/drugs)

Receptors: 5HT3, vagal, dopamine?
Drugs: Prochlorperazine (blocks vagal stimulation)

57

Palliation of N/V: Toxins stimulating CTZ (receptors/drugs)

Receptors: Dopamine, 5-HT3
Drug: Ondansetron (emetogenic chemo); prochlorperazine (opiates)