GI Flashcards
(120 cards)
1
Q
Scopolamine is a
A
Cholinergic Antagonist
2
Q
Scopolamine can come in what forms?
A
patch and injectable
3
Q
Scopolamine mechanism of action
A
Blocks the acetylcholine at parasympathetic sites (smooth muscle, secretary glands, CNS)
Reduces histamine and serotonin activity
4
Q
Scopolamine onset and duration
A
onset - 6-8 hours
duration - 72 hours
5
Q
Scopolamine side effects
A
similar effect to atropine - bradycardia then tachycardia, flushing, orthostatic hypotension, cognitive impairment, psychosis and hallucinations
6
Q
Scopolamine is contraindicated in
A
narrow angle glaucoma
7
Q
Phenothiazines
Butyrophenones
Benzamides are all
A
Dopamine receptor antagonists
8
Q
Phenothiazine include
A
Prochlorperazine
9
Q
Butyrophenones include
A
Haloperidol
Droperidol
10
Q
Benzamides include
A
Metoclopramide
Thrimethobenzamide
11
Q
MOA for Dopamine receptor antagonists
A
acts primarily on the CTZ and afferent pathways in the gut
Antagonize D2 dopamine receptors in area postrema and peripheral sites
M1-muscarinic and H1-histamine blocking effects
Metoclopramide has weak 5-HT3 blockage at higher doses
12
Q
Side effects of Dopamine receptor antagonists
A
Extrapyramidal reactions (Dystonia), tardive dyskinesia, QT prolongation, CNS/psych effects, hyperprolactinemia, Hypotension
13
Q
Prochlorperazine onset and duration
A
onset - PO = 30-40 min
rectal approximately 60 min
Duration = 3-4 hours oral, 3-12 rectal
14
Q
Metoclopramide duration
A
1-2 hours
15
Q
Ondansetron and Granisetron are
A
Serotonin receptor antagonists
16
Q
Ondansetron MOA
A
Blocks serotonin centrally and peripherally
17
Q
Ondansetron onset and peak
A
onset = approx 30 min
peak = 1-2 hours
18
Q
Ondansetron side effects
A
QT prolongation, dizziness, confusion, SOB, constipation
19
Q
Ondansetron major interactions
A
amiodarone
QT prolonging agents
CYP3A4
20
Q
Cannabinoids MOA
A
activates cannabinoid receptors
21
Q
Cannabinoids onset, peak, duration
A
onset - 30-60 min
peak - 2-4 hours
duration - 4-6 hours
22
Q
Cannabinoids side effects
A
euphoria
CNS changes
abdominal pain
vomiting
flushing
palpitations
hypotension
xerostomia
vertigo
23
Q
Promethazine
Meclizine
Dimenhydrinate
A
Histamine antagonists
24
Q
Promethazine MOA
A
blocks mesolimbic dopaminergic receptors in postsynaptic sites
Blocks the release of hormones from the hypothalamus
Blocks histamine 1 receptors in the brainstem
25
Promethazine Onset and duration
onset - IV ~5 min, PO/IM ~ 20 min
duration - 4-6 hours
26
Promethazine Side effects
EKG changes, anticholinergic effects, CNS depression, orthostatic hypotension
27
Meclizine MOA
Blocks HI histamine receptor and prevents vasodilation, increased capillary permeability, bronchoconstriction and spasmodic contraction of GI smooth muscles
depresses labyrinth excitability and vestibular stimulation
28
Meclizine onset and duration
onset - 1 hour
duration - ~24 hours
29
Meclizine side effects
sedation
HA
vomiting
blurred vision
30
Meclizine avoid in
glaucoma, asthma, urinary retention, or pyloric/duodenal obstruction
31
Dimenhydrinate MOA
binds to H1 receptor sites in peripheral sites including GI tract, resp tract, and blood vessels
blocks chemoreceptor trigger zones
Depresses labyrinthine function and vestibular stimulation
Central anticholinergic activity
32
Dimenhydrinate onset and duration
onset = up to 30 min for IM and PO
duration = 4-6 hours
33
Dimenhydrinate rarely causes
SJS
34
Dimenhydrinate do not use with
abx that are known to cause ototoxicity
35
Opioid Agonists
Serotonin receptor modulators
bile acid sequestrants
anti-spasmodics
antimicrobial agents
Can all be used for
Diarrhea and IBS-D
36
MOA Opioid Agonists
Activation of opioid receptors in the smooth muscle of the GI tract. Alters peristalsis by preventing smooth muscle contraction and relaxation. Reduces stool volume and can prevent electrolyte depletion
37
before using opioid agonists you should correct any
fluid/electrolyte imbalances
38
Do not use opioid agonists with
infectious diarrhea/toxic megacolon
39
Loperamide
Diphenoxylate/Atropine
Octreotide
Eluxadoline are all
opioid compound drugs
40
MOA Loperamide
also increases IAS and EAS tone
41
Diphenoxylate/ atropine - why does it contain atropine
contains small amount of atropine to prevent abuse
42
Octreotide MOA
Inhibits serotonin release
inhibits secretion of gastrin, VIP, insulin, glucagon, secretin, motilin and pancreatic polypeptide
43
MOA Eluxadoline
Binds to mu, kappa and delta opioid receptors in the intestinal lumen
decreases intestinal motility without causing constipation
44
Eluxadoline considerations
can cause acute pancreatitis in pts with cholecystectomy
Do not give to pts with EtOH abuse
do not use in pts with h/o intestinal obstruction
can cause CNS depression
45
Alosetron
Tegaserod are
serotonin receptor modulators
46
Alosetron is used for
chronic >6 months severe IBS-D
47
Alosetron MOA
selective 5-HT3 agonist
acts on receptors in the enteric neurons in addition to receptors in other locations centrally and peripherally
affects visceral pain, colonic transit, and alters secretions in the GI tract
48
Alosetron can rarely cause
ischemic colitis
do not use in pts with h/o GI obstruction, crohns, diverticulitis, vasculopathy, thrombophlebitis, hypercoagulable conditions
49
Alosetron instructions
take on an empty stomach to increase absorption
50
MOA of bile acid sequestrants
Bind to bile salts in the intestine
inhibits reuptake of bile salts
increases fetal loss of bile salt bound LDL cholesterol
51
Bile acid sequestrants instructions
do not administer within 4-6 hours of other medications - may interfere with absorption
52
Rifaximin
Metronidazole
Ciprofloxacin
Amoxicillin
Neomycin
Antimicrobials
53
Hyoscyamine
Dicyclomine are
anti-spasmodics
54
MOA anti-spasmodics
Blocks acetylcholine at parasympathetic receptors
Antagonist of histamine and serotonin
55
Contraindications of anti-spasmodics
MG
hypersensitivity to delladonna
UC
myocardial ischemia
56
Isosmotic
Hyperosmotic
stimulant laxatives are all types of
bowel preps
57
Isosmotic Preps are the
PEG (polyethylene glycol) based electrolyte lavage solutions
58
PEG MOA
the osmotic effect of PEG causes water to be retained in colon --> produces watery stool - think fluid overload
does not work on the nerves or muscles of the gut
no permeation of cell membranes
59
Advantages of PEG-based preps
no mucosal damage
minimal osmotic fluid shifts
safer than sodium phosphate based solutions in pts with impaired renal function, cirrhosis, etc
60
Disadvantages of PEG based preps
large volume of fluids
unpalatable taste if not flavored
61
Hyperosmotic Preps contain a higher concentration of
salts and other dissolved materials than normal tissues
62
MOA of hyperosmotic preps
increases intraluminal water (pulls water into the intestine) by promoting the passage of extracellular fluid across the bowel wall (significant fluid and electrolyte shifts)
High Na concentration --> osmotic retention of water in the bowel --> causing a watery diarrhea
63
Advantages Hyperosmotic preps
small volume (though additional fluids must be consumed as well)
more palatable than PEG - based solutions
64
Disadvantages of hyperosmotic preps
potential for causing fluid and electrolyte shifts by drawing water into the intestine
renal damage
65
Risks of NaP Bowel Preps
Acute phosphate nephropathy - form of renal insufficiency characterized by calcium phosphate deposition within the kidneys
66
Stimulant laxatives MOA
increased smooth muscle activity (peristalsis)
67
Examples of stimulant laxatives
senna, bisacodyl, sodium picosulfate
68
Senna MOA
increases rate of motility --> enhances colonic transit and inhibits water and electrolyte secretion
69
Senna is often used as adjunct to
PEG regimens
70
Bisacodyl MOA
stimulation of small intestinal enzyme secretion and increased motor activity within the colon
71
Clenpiq MOA
prodrug - metabolized in the gut by gut bacteria, stimulating peristalsis
72
Contraindications of Clenpiq
creatinine clearance < 30 ml/min (mild to moderate kidney disease)
73
Split dose regimen is
part of the purgative is taken the evening before and the remainder is taken the morning of the procedure - has been demonstrated to be more effective and better tolerated than single dose taken the evening before the procedure
74
Contraindications for NaP bowel preps
peds
elderly pts
liver failure
CHF
bowel obstruction
renal insuff or failure
75
Colonoscopy should be performed within
8 hours of the last dosing
76
Diet before colonoscopy
~ 2 days before = eat low-fiber
day before = don't eat solid foods, consume only clear fluids
day of = clear fluids only, don't eat or drink anything 2 hours before the procedure
77
GERD antacids MOA
Neutralize acid (increase pH)
78
Calcium based - calcium hydroxide
Aluminum based - aluminum hydroxide
Magnesium based - magnesium hydroxide
are all
antacids
79
GERD: surface agents MOA
coats esophageal/gastric mucosa, creates physical barrier between mucosa and acid
short term management of GERD sx's, swallow after meals, avoid drinking/eating afterwards
80
Sucralfate
Sodium alginate
Bismuth
are all
surface agents
81
GERD: H2RAs MOA
block stimulation of gastric parietal cells by competing with histamine at H2 receptors
less effective than PPIs, not effective for h. pylori
82
GERD: H2RAs you can develop
tolerance within 4-6 weeks
83
Crimetidine
rantidine
famotidine
are all
GERD: H2RAs
84
GERD: PPIs MOA
block the gastric H/L-ATPase, inhibiting gastric acid secretion
most effective acid suppressing med, use for GERD, dyspepsia, PUD, H. pylori
85
Omeprazole
Pantoprazole
Lansoprazole
Dexlansolprazole
Esomeprazole
Rabeprazole
are all
PPIs
86
Risks of PPIs
malabsorption of some minerals and vitamins (mag, calcium, B12)
risk of diarrheal illnesses - C. diff
increased bacterial pneumonia
gastric polyps
87
PUD/ H. pylori: Bismuth MOA
stimulates prostaglandin/ mucous/ bicarbonate production in the stomach
mild antimicrobial activity against H. pylori
reduces inflammation
88
Bismuth subsalicylate or Pylera (combo bismuth + metronidazole + tetracycline) used for
PUD/ H. pylori
89
PUD: Misoprostol MOA
synthetic prostaglandin E1 analog
Prostaglandins inhibit acid secretion by reducing the ability of parietal cells to respond to histamine
90
Use for Misoprostol
prevention of NSAID-induced gastric ulcers
91
Example of a misoprostol
Cytotec
92
Caution of Misoprostol (cytotec)
can induce uterine contractions
93
Metoclopramide
Doperidone
Erythromycin
are all
prokinetic agents
94
MOA of metoclopramide
dopamine antagonist
enhances upper GI tract response to Ach to enhance motility; increases colon motility and shortens transit time
95
Metoclopramide BBW
can cause tardive dyskinesia
96
Misoprostol BBW
contraindicated in pregnancy or women of childbearing age (can cause birth defects, premature birth, abortion, uterine rupture)
97
Domperidone MOA
Peripheral dopamine antagonist
increases esophageal peristalsis, gastric motility, gastric emptying decreases small bowel transit time
98
Domperidone BBW
increased risk of cardiac arrhythmias or sudden cardiac death
contraindicated for pts with prolactinomas
99
erythromycin MOA
macrolide antibiotic
motilin agonist - increases gastric contractions
100
Erythromycin caution with...
Myasthenia gravis - may exacerbate or cause symptoms
101
Neostigmine MOA
acetylcholinesterase inhibitor
102
Neostigmine Uses
acute colonic pseudo-obstruction (primarily used for MG)
103
Flares of IBD treatment
Glucocorticoids - hydrocortisone, prednisone, budesonide
Aminosalicylates - 5-ASA, sulfasalazine, mesalamine
104
Aminosalicylates MOA
work topically on affected/inflamed areas of mucosa; anti-inflammatory and immunosuppressive activity
Sulfasalazine - precursor to 5-ASA
105
Thiopurines MOA and use
immunosuppressant
induce and maintain remission in both UC and Crohn's
106
Thiopurines BBW
chronic immunosuppression increases the risk of malignancy
107
Thiopurines avoid use with
allopurinol --> leukopenia
108
Methotrexate MOA
Immunosuppressant, anti-inflammatory for IBD
acts as a folate antagonist, inhibiting DNA synthesis, repair and cellular respiration
109
Methotrexate use
induce and maintain remission in Crohn's disease, less commonly used for UC
110
Methotrexate BBW
serious toxic/fatal side effects
closely monitor for bone marrow, liver, lung, skin and kidney toxicity
Teratogenic
111
Supplement with ________ when taking methotrexate
Folic acid
112
IBD: biologics MOA
bind and sequester TNF to decrease inflammatory response
113
Triple therapy for H. pylori
clarithromycin
amox (or metronidazole)
PPI
114
Quad therapy for H. pylori
bismuth subsalicylate
tetracycline
metronidazole
PPI
115
Biologic ("mab"s) use for IBD
maintenance for moderate - severe IBD (mostly for crohn's, infliximab, vedolizumab also for UC)
116
Glucocorticoids MOA
inhibits production of inflammatory cytokines and inhibits migration of inflammatory cells to affected area
117
Glucocorticoid use
moderate-severe Crohn's and UC, helpful in early treatment and during flares
118
If giving Misoprostol to a women in childbearing age you need
a pregnancy test 2 weeks before and every month during the use of this drug
119
Metoclopramide is for ______ term use only
short
< 12 weeks
120
Erythromycin should only be used for a max of
4 weeks d/t tachyphylaxis
