Constipation, Diarrhea, Nausea/Vomiting

Question 1

methyl cellulose / psyllium MOA

Answer 1

dietary fiber and bulk forming laxative - hydrophilic muciloid that forms gelatinous mass when mixed with water

Question 2

methyl cellulose / psyllium AE

Answer 2

allergic reactions, flatulence, borborygmi, intestinal obstruction

Question 3

DDI of metamucil

Answer 3

inhibit coumarin absorption

Question 4

DDI of citrucel (cellulose)

Answer 4

bind & impede drug absorption

Question 5

uses for dietary fibers

Answer 5

both for constipation as a stool former and to treat IBS diarrhea by forming bulkier stool

Question 6

AE for laxatives

Answer 6

1. abuse

2. lag time leads to overdose and the following shit storm

Question 7

lactulose MOA

Answer 7

not absorbed and produces osmotic laxative effect, fecal acidifier and TRAPS ammonia in ammonium form for excretion

Question 8

stimulant laxatives (3)

Answer 8

bisacodyl (dulcolax)
senna
cascara sagrade extract

Question 9

MOA of stimulant laxatives

Answer 9

mostly on LARGE bowel

1. increase permeability of mucosa
2. increas back diffusion of H20 & electrolytes
3. propulsive contractility of colon
4. stimulate prostaglandin synthesis

Question 10

AE for bisacodyl (dulcolax)

Answer 10

excessive fluid loss, electrolyte loss, intestinal enterocyte damage

Question 11

PK for bisacodyl (dulcolax)

Answer 11

prodrug - bacteria activated, is administered in enteric coated tab

Question 12

AE for senna

Answer 12

abdominal pain, nephritis, melanotic pigmentation of colonic mucosa, abnormal urine coloration

Question 13

PK for senna

Answer 13

natural derivative of senna/cascara - more gentle than the synthetics

Question 14

castor oil MOA

Answer 14

rapid-acting and effective anionic surfactant - produces catharsis

Question 15

castor oil AE

Answer 15

colic, dehydration, electrolyte imbalance - can induce uterine contraction in pregnancy

Question 16

2 surfactant laxatives

Answer 16

castor oil & docusate sodium (colace)

Question 17

docusate sodium (colace) MOA

Answer 17

anionic surfactant, weakly active, primarily used as stool softener, no effect on intestinal peristalsis

Question 18

AE for docusate sodium (colace)

Answer 18

irritate mucosa and increase other drug absorption

Question 19

CI for docusate sodium (colace)

Answer 19

not for use during abdominal pain, n/v

Question 20

long term or short term use for docusate sodium (colace)

Answer 20

short term

Question 21

lubiprostone MOA

Answer 21

activates intestinal Cl channels in a protein kinase-A independent fashion - increases intestinal fluid secretion & motility & alleviates symptoms of idiopathic constipation

Question 22

Tegaserod MOA

Answer 22

activation of 5-HT4 recetpors in GI tract - effective motility stimulant (also 5-HT2b antagonist)

Question 23

Tegaserod AE

Answer 23

5-HT2b antagonist activity has shown CV adverse effects

Question 24

opiate (1)

Answer 24

loperamide

Question 25

loperamide effects

Answer 25

1. dec salivary, gastric, intestinal secretions 2. dec motility of stomach & intestines 3. inc muscle tone but dec cramps 4. inc tone of sphincters 5. inc contact time and reabsorption

Question 26

loperamide MOA

Answer 26

interacts with intestinal opioid receptors and binds to and inhibits calcium binding protein calmodulin

Question 27

anticholinergic for motion sickness

Answer 27

scopolamine

Question 28

MOA of scopolamine

Answer 28

blocks activation of muscarinic receptors and dec cochlear sensation of motion

Question 29

AE of scopolamine

Answer 29

sedation, extrapyramidal (drowsiness, dry mouth)

Question 30

scopolamine PK

Answer 30

patch placed behind ear before trip

Question 31

use for scopolamine

Answer 31

MS prophylaxis

Question 32

H1 antihistamines - antiemetics

Answer 32

cyclizine, meclizine, chlorpheniramine

Question 33

which are piperazine derivative H1 antihistamines

Answer 33

cyclizine and meclizine

Question 34

pharm effects of cyclizine and meclizine

Answer 34

significant anti-cholinergic effects

Question 35

AE for H1 antihistamines

Answer 35

sedation, anticholinergic

Question 36

which H1 antihistamine has the least sedative & GI AE

Answer 36

chlorpheniramine

Question 37

clinical use for cyclizine

Answer 37

OTC to counter MS

Question 38

clinical use for meclizine

Answer 38

vertigo and menier's disease

Question 39

antidopaminergics (3) - antiemetics

Answer 39

chlorpromazine, droperidol, metoclopramide

Question 40

chlorpromazine MOA

Answer 40

blocks DA receptors in CTZ and centrally acting anticholinergic

Question 41

clinical utility for chlorpromazine

Answer 41

n/v, intractable hiccough

Question 42

droperidol MOA

Answer 42

blocks DA receptors in CTZ

Question 43

droperidol clinical utility

Answer 43

poor antipsychotic but highly useful antiemetic

Question 44

metoclopramide MOA

Answer 44

DA receptor antagonist that blocks chemotherapeutic induced activation of D2 receptors in CTZ - also stimulates gastric emptying

Question 45

metoclopramide clinical utility

Answer 45

prophylaxis prior to cancer chemo & prevention of post-op n/v

Question 46

serotonin antagonists

Answer 46

granisetron, dolasetron

Question 47

MOA of serotonin antagonists

Answer 47

5-HT antagonist blocks receptors in stomach/SI 1. block signal to CTZ and to VC 2. block 5-HT3 receptor in CTZ

Question 48

which serotonin antagonist has longest half life

Answer 48

dolasetron

Question 49

clinical utility for methylprednisolone

Answer 49

anti-emetic effect through prevention of prostaglandins - given with aforementioned entiemetics to increase their potency and reduce side effect profile

Question 50

aprepitant MOA

Answer 50

substance P/neurokinin 1 (NK1) antagonist - crosses BBB and inhibits central emesis

Question 51

PK of aprepitant

Answer 51

half life 9-13 hours, given orally | metabolism by CYP3A4

Question 52

lorazepam utility

Answer 52

effective for anticipatory vomiting because causes somnolence and amnesia