B5-048 GI Pharmacology Flashcards
1
Q
most common secretory disorders
A
acid-peptic disease
GERD
2
Q
most common motility disorders
A
vomiting
diarrhea
constipation
3
Q
list the mediator, receptors, and antagonist for the neural pathway
A
mediator: Ach
receptor: muscarinic
antagonist: anti-muscarinic
4
Q
list the mediator, receptors, and antagonist for the endocrine pathway
A
mediator: gastrin
receptor: CCKB
antagonist: H2 blocker
5
Q
list the mediator, receptors, and antagonist for the paracrine pathway
A
mediator: histamin
receptor: H2
antagonist: H2 blocker
6
Q
classes that inhibit gastric acid secretion
2
A
proton pump inhibitors
H2-antagonists
7
Q
class that neutralizes gastric acid secretion
A
antacids
8
Q
irreversibly inhibit the parietal cell proton pump
A
benzimidazole
PPI
9
Q
proton pump inhibitors are […] that are […] at a neutral pH
A
prodrugs
inactive
10
Q
- activated by acid, but unstable at low pH
- enteric coating only dissolves at alkaline pH
A
PPIs
11
Q
how do PPIs maintain efficacy even with chronic use?
A
parietal intracellular canaliculi are upstream from the proton pump
remains acidic even when proton pump is inhibited
12
Q
-prazole
A
proton pump inhibitor
13
Q
most effective drug for suppressing gastric acid secretion
supresses 90-95%
A
proton pump inhibitors
14
Q
with prolonged use, diarrhea occurs due to GIT bacterial overgrowth from removal of natural acidic barrier
A
PPIs
15
Q
inhibition of gastric acid secretion persists after withdrawal of drug due to irreversible inhibition
A
PPIs
16
Q
-tidine
A
H2 receptor antagonists
17
Q
reversible block of H2 receptors leading to decreased H+ secretion by parietal cells
A
H2 antagonists
18
Q
- OTC preparations that block acid secretion for about 6 hrs
- only inhibits 60-70% of acid secretion
A
H2 receptor antagonist
19
Q
especially effective againsts nocturnal acid secretion
A
H2 receptor antagonists
largely driven by histamine
20
Q
relative potency of H2 receptor antagonists
A
famotidine > nizatidine = ranitidine > cimetidine
21
Q
block H2 receptors selectively to reduce gastric acid and pepsin secretion
A
H2 receptor antagonists
22
Q
20% failure in ulcer patients who smoke and elderly
A
H2 receptor antagonists
23
Q
should not be used in combination with PPI
A
H2 receptor antagonists
reduce efficacy
24
Q
most common side effects of H2 receptor antagonists
A
diarrhea
headache
fatigue
myalgias
constipation
bradycardia
25
mental changes like confusion, hallucinations, and agitation may occur with IV infusion of [...] in elderly or renal/hepatic dysfunction
H2 receptor antagonists
26
* endocrine side effects due to androgen receptor binding
* gynecomastia, impotence, galactorrhea
cimetidine
27
interferes with cytochrome P450 pathways
cimetidine
28
antacids
| 3
* aluminum hydroxide
* calcium carbonate
* aluminum hyroxide/magnesium hydroxide
29
weak bases that neutralize gastric HCl to form salt and water
antacids
30
popular due to low cost and rapid action but may cause rebound acid oversecretion
antacids
31
rebound acid secretion
antacids
32
why are magnesium and aluminum typically combined in an antacid preparation?
mag causes diarrhea
aluminum causes constipation
| offset each other
33
* establish protective coating on peptic ulcers
* limit exposure to acid/pepsin
musocal protective agents
34
binds selectively to necrotic ulcer tissue and acts as a barrier
sucralfate
| mucosal protective agent
35
common side effect of sucralfate
constipation
36
requires acid pH for activation so should not be given with PPIs, H2 antagonists, or antacids
sucralfate
37
methyl analog of PGE1
misoprostol
| muscoal protective agent
38
binds to PG receptors on parietal cells to inhibit acid secretion
misoprostol
39
used to prevent NSAID induced ulcers
misoprostol
40
most common adverse effects of misoprostol
diarrhea
abdominal pain
41
may cause abortion by stimulating uterine contractions
misoprostol
42
* protective coating of ulcers
* antibacterial against H pylori
bismuth subsalicylate (pepto)
| mucosal protective agent
43
will darken tongue and stools as side effect
bismuth subsalicylate
44
gram negative bacterium causing inflammatory gastritis that contribute to peptic ulcers
H. pylori
45
are single antibiotic regimens effective against H pylori?
no
46
triple therapy for Peptic Ulcer Disease/H. pylori
* clarithromycin
* amoxicillin
* PPI
| if allergic to pen, metronidazole
47
mucosal protective agents
| 3
* bismuth subsalicylate
* misoprotrol
* sucralfate
48
single most commonly reported drug side effect
nausea/vomiting
49
saline laxatives
| 2
magnesium citrate
sodium phosphate
50
act by osmotic force to draw water into the intestinal lumen -> distension -> peristalsis
saline laxatives
51
intensely bitter taste
saline laxatives
52
trihydroxy alcohol that acts in rectum as lubricant and hygroscopic agent -> water retention -> perstalsis
glycerin
53
hydrolyzed to organic acids -> acidify luminal contents -> draw water into lumen -> increase colonic propulsive motility
| 4
lactulose
sorbitol
lactitol
mannitol
54
poorly absorbed and retain added water by their high osmotic pressure
PEG solutions
55
typical colonoscopy prep
3-4 L over 3-4 hours
PEG solution
56
mixtures of sodium sulfate, sodium bicarb, sodium chloride, and postassium chloride in isotonic solution
PEG solution
57
osmotically active laxatives
saline
sugars
PEG solution
58
act directly on enterocytes, neurons and muscle to induce low-grade inflammation to increase intestinal motility
stimulant/irritant laxatives
59
diphenylmethane derivatives
| 2
bisacodyl
phelophthalein (not really used, carcinogen)
60
bisacodyl should be taken at [time of day]
and [method of intake] to avoid activation in the stomach
bedtime
swallowed without chewing
61
long term use causes melanomic pigmentation of colonic mucosa and "cathartic colon"
anthraquinones
62
aloe
cascara sagrada
senna
| are...
anthraquinones
63
* local irritant that increases intestinal secretion and motility
* seldom used due to taste and toxic potential
castor oil
| ricinoleic acid
64
bulk forming laxatives
| 3
methylcellulose
lactulose
polycarbophil
65
bulk forming laxatives require adequate
hydration
66
stool softners
mineral oil, glycerin suppositories, docusate sodium
67
ofter prescribed to prevent straining in hospitalized patients
docusate sodium
68
* Mu agonists relatively selective for intestinal opioid receptors
* inhibit ACh to decrease motility
| 3
loperamide
difenoxin
diphenoxylate
| low efficacy opiods
69
very effective against traveler's diarrhea
works quickly
loperamide
70
antidiarrheals
| 4
* mu agonists
* kaolin/pectin
* bismuth subsalicylate
* somatostatin/octreotide
71
* acts by absorbing compounds and resumably bindings potential intestinal toxins
* increases viscostiy of luminal contents
kaolin/pectin slurry
72
* reduces portal and splanchnic blood flow
* inhibits secretion of intestinal hormones
* reduces intestinal fluid and pancreatic secretion
* reduces gallbladder contractility
somatostain/octreotide
73
histamine H1 antagonists
| 4
* dimenhydrinate
* diphenhydramine
* cyclizine
* meclizine
74
produce sedation and antimuscarinic activity to prevent motion sickness
Histamine H1 antagonists
75
D2 antagonists
| 2
metoclopramide
trimethobenzamine
76
5-HT3 antagonists
| 3
ondansetron, granisetron, dolasetron
| **-setron**
77
used for nausea and vomiting during cancer chemotherapy
5-HT3 antagonists
-setron
78
NK-1 antagonists
| 3
aprepitant
fosaprepitant
rolapitant
| **-pitant**
79
-setron
5-HT3 antagonists
80
-pitant
NK-1 antagonists
81
anti-emetics classes with unclear MOA
D2, 5-HT3, and NK-1 antagonists
82
phenothiazines and benzodiazepines used as anti-emetics
| 4
p: chlorpromazine, prochlorperazine
b: lorazepam, alprazolam
83
marijauna derivatives used as anti-emetics
| 2
THC
dronabinol
84
used as a prophylactic in patients receiving cancer chemotherapy
dronabinol
85
adverse effects include increaased central sympathetic chain activity causing mood changes, laughing, paranoid reactions, and thinking abnormalities
THC/dronabinol
86
artificial sweeteners, a-glucosidase inhibitors, osmotic laxatives cause....
osmotic diarrhea
87
caffeine, chemotherapeutic agents, colchicine, metformin, NSAIDs, simvastin, and cholinesterate inhibitors cause...
secretory diarrhea
88
cholinesterase inhibitors and antibiotic drugs cause...
motility diarrhea
89
NSAIDs, oral contraceptives, PPIs, SSRIs, stimulant laxatives, chemo agents cause...
inflammatory diarrhea
90
drugs that draw water and ions into the intestinal luman cause...
osmotic diarrhea
91
drugs that cause and imbalance between absorption and secretion into lumen cause...
secretory diarrhea
92
large volumes of stool, lack of red or white cells in stool, absence of other symptoms indicates
secretory diarrhea
93
drugs that increase or decrease MMC activity cause...
motility diarrhea
94
hypomotility results in stasis that allows for
bacterial overgrowth
95
drugs that disrupt epithelium in GI tract cause...
inflammatory diarrhea
96
associated with collagenous and lymphocytic collitis
PPIs
97
SSRIs are commonly associated with [...] diarrhea
inflammatory
| paroxetine, sertraline
98
drugs that commonly produce constipation
anticholinergic
antidepressants (TCAs)
diphenhydramine
trimethaphan
iron supplements
Opiods
## Footnote
there's more but i'm lazy
99
constipation from opiods is
does dependent and predictable
100
no tolerance develops toward
opiod induced constipation
101
coadministration of these with opiods will help prevent constipation
| 2
* naloxone
* methylnaltrexone
102
mucosal agent that can protect GI lining from acid, but does not darken tongue or stools
sucralfate
103
requires acidic environment for conversion to active drug form
PPIs
| -prazole
104
bisocodyl and senna are [...] laxatives
irritant
105
reduce the protection of protective prostaglandins that shield stomach wall from degradation by low pH environment
non selective COX inhibitors
| NSAIDs
106
low efficacy opiod with selectivity for the GI tract that reduces motility and symptoms of travelers diarrhea
diphenoxylate
107
antibiotics used in the treatment of H pylori in PED
amoxicillin
metronidazole
108
pro-drugs that require the conversion to an active drug in the acid containing canaliculi in the gastric parietal cells in order to bind and inhibit
PPIs
| -prazoles
109
antihistamine selective for H2 receptors that reduce acid production and esophageal irritation
-tidines
| rantidine, nizatidine
110
what class does trimethobenzamide belong to
D2 receptor antagonist
| antiemetic
