GI Anatomy
• Oral cavity
• Pharynx
• Esophagus
• Stomach
• Liver
• Pancreas
• Small intestine
• Large intestine
• Neural and hormonal control
o low PH in stomach to help with food digestion and infection prevention
2
Stomach Spotlight
• 3 functional parts of stomach
o cardiac zone
o gastric zone
▪ contains special cells:
• Parietal cells: produce and secrete hydrochloric acid
o Hydrochloric acid secretion stimulated by: caffeine, ETOH, food,
chocolate, parietal cells; may also be due to emotional stress, large
fatty meals
• Chief cells: secrete pepsinogen
o Becomes pepsin with presence of acid
• Mucus cells: secrete surface epithelial cells for protective coating
▪ An imbalance leads to GI issues (PUD, esophageal CA, GERD, etc.)
o pyloric zone
3
• Stomach secretions
o Acidic pH
o Hydrochloric acid- promote food digestion and as a line of defense
o Bicarbonate- buffer to acid
o Pepsinogen (precursor to pepsin)- aids in digestion of protein
o Salivary amylase- aids in digestion of carbohydrates
o Intrinsic factor
o Mucus
o Prostaglandins
4
Deeper look at Parietal Cells
• Three types of receptors on cell walls: Acetylcholine (ACh); Histamine; Gastrin
o When these receptors are occupied with stimulant the cell produces hydrochloric
acid
o When histamine is occupied, adenylate cyclase is produced which then converts
ATP to cAMP to provide energy required for proton pumps
▪ Proton pump: works to transport hydrogen ions needed for hydrochloric
acid production
o ACh and gastrin receptor proton pumps are driven by calcium ions
▪ Certain meds block ACh receptors = lower hydrochloric acid production
• Help to release intrinsic factor
5
GI Functions
• Processes and breaks down ingested food and fluids
• Absorb necessary components
• Digestion and absorption
Carbs • Digestion starts in mouth and then intestine
• Breaks down into simple sugars
• Fructose, glucose, galactose
Proteins • Split into peptides in the stomach and intestine
• Further break down to amino acids
Lipids • Triglycerides are emulsified by bile in SI
• Certain enzymes act on fats and form monoglycerides and
free fatty acids
6
o Fat soluble vitamins
o Water soluble vitamins
o Electrolytes, Drugs, Water
7
Common Digestive System Disorders
Anorexia Bulimia Vomiting
• Loss of appetite and poor intake
• Afraid of gaining weight
• May have very small portions of
food
• Severe F+E imbalances! Can
cause damage systemically
• Cycle of binge eating and force
vomiting, taking laxatives, and
possibly starving self to prevent
weight gain
• Can cause damage to oral
cavity, esophagus; can cause
diarrhea, constipation, F+E
imbalances!
• Can be anorexic
• forceful expulsion of chyme from
the stomach and sometimes from
the intestine
• vomiting center in the medulla
coordinates the activities involved
in vomiting
o activated by: GI distention,
pain, stress, increased ICP,
motion sickness, stimulation of
chemoreceptors, toxins
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Constipation Diarrhea
• Less frequent bowel movements than normal, and
small hard stools result
• Symptom, not a disease
• Acute or chronic
• May alternate with diarrhea
• Causes: narcotics, aging, inadequate fluid intake,
muscle weakness, neurological disorders, some
antacids, obstructions
• Chronic constipation can cause hemorrhoids and
diverticulitis
• Can cause fecal impaction
• Criteria: 3+ months of straining, lumpy hard stools,
incomplete evacuation with 25%+ BMs, <3
BMs/wk
• TX: laxatives, stool softeners, diet modifications,
treat cause, increase physical activity
• Excessive frequency of stools, usually of loose or
watery consistency
• May be due to infection, medications, IBS,
virus/bacteria, nutritional factors; tumors, DM,
Addison’s disease, AIDs
• May be acute or chronic
• Frequently accompanied by nausea and vomiting
when infection or inflammation of the digestive tract
develops, but can occur alone
• May lead to F+E imbalances, acid/base imbalance,
malnutrition, dehydration
• Monitor for frank blood, occult blood, melena,
steatorrhea
• Chronic diarrhea= lasts >4 weeks; assoc. with
frequent diarrhea, fever, loss of appetite, N/V, wt loss
• Need F+E; decrease frequency, prevent wt loss
• TX: antidiarrheal, treat cause
9
Laxatives
• Bulk forming
o High fiber
o Absorb water to increase bulk
o Distend bowel to initiate reflex bowel activity
o Examples: Psyllium (Metamucil), Methylcellulose (Citrucel)
• Emollient (stool softeners, lubricant laxatives)
o Promote more water and fat in the stools
▪ Stool softeners: docusate salts (Colace, Surfak)
o Lubricate the fecal material and intestinal walls
▪ Lubricants: mineral oil
• Hyperosmotic
o Increase fecal water content
o Results in bowel distention, increased peristalsis, and evacuation
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o Examples: Polyethylene glycol (PEG), Sorbitol, lacitol, glycerin, Lactulose (also
used to reduce elevated serum ammonia levels)
• Saline
o Increase osmotic pressure within the intestinal tract, causing more water to enter
the intestines
o Results in bowel distention, increased peristalsis, and evacuation
o Examples: Magnesium hydroxide (Milk of Magnesia), Magnesium citrate
o ***caution for adverse effect of hypermagnesemia maybe review this??
• Stimulant
o Increases peristalsis via intestinal nerve stimulation
o Examples: Senna (Senokot), Bisacodyl (Dulcolax)
Nursing Implications for Laxatives
• Obtain a thorough history of presenting symptoms, elimination patterns, and
allergies
11
• Assess fluid and electrolytes before initiating therapy
• Inform patients not to take a laxative or cathartic if they are experiencing nausea,
vomiting, or abdominal pain
• A healthy, high-fiber diet and increased fluid intake should be encouraged as an
alternative to laxative use
• Long-term use of laxatives often results in decreased bowel tone and may lead to
dependency
• All laxative tablets should be swallowed whole, not crushed or chewed, especially if
enteric coated
• Patients should take all laxative tablets with 6 to 8 oz of water
• Give bisacodyl with water because of interactions with milk, antacids, and juices.
• Inform patients to contact their prescribers if they experience severe abdominal pain,
muscle weakness, cramps, or dizziness, which may indicate possible fluid or
electrolyte loss
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Peripherally Acting Opioid Antagonists
• Treatment of constipation related to opioid use and bowel resection therapy
• Block entrance of opioid into bowel
• Allow bowel to function normally with continued opioid use
• Examples: Methylnaltrexone (Relistor), Alvimopan (Entereg), Naloxagol (Movantik)
Antidiarrheals
• Adsorbents
o coat walls of GI tracts and eliminate causes (like bacteria) in stools
o Examples: bismuth subsalicylate (Pepto-Bismol), activated charcoal, and
antilipemic drugs colestipol, cholestyramine
▪ bismuth subsalicylate is a form of aspirin
o AE: increased bleeding times, constipation, dark stools, confusion, blue tongue
o decrease the absorption of many drugs, including digoxin, quinidine, and
hypoglycemic drugs
13
▪ cause increased bleeding time and bruising when given with anticoagulants
• Antimotility drugs (anticholinergics and opiates)
o opiates
▪ Decrease bowel motility and reduce pain by relief of rectal spasms
▪ Decrease transit time through the bowel, allowing more time for water and
electrolytes to be absorbed
▪ Examples: paregoric, opium tincture, codeine, over-the-counter (OTC)
loperamide (Immodium), diphenoxylate(Lomotil)
▪ AE: drowsiness, respiratory depression, hypotension, etc.
o Anticholinergics
▪ Slow peristalsis by reducing the rhythmic contractions and smooth muscle
tone of the GI tract
▪ Drying effect
▪ Reduce gastric secretions
▪ Used in combination with adsorbents and opiates
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▪ Example: Atropine
• Probiotics (also known as intestinal flora modifiers and bacterial replacement drugs)
o AKA intestinal flora modifiers and bacterial replacement drugs
o Bacterial cultures of Lactobacillus organisms
work by: supplying missing bacteria to the GI tract, suppressing the growth of
diarrhea-causing bacteria
• Example: Lactobacillus acidophilus (Bacid)
15
??? that’s not an opioid!?!
But it does act on opioid
receptors (Mu receptors)
*CAUTION! Do not use on
children, especially who have
flu-like symptoms, recovering
from chickenpox.... WHY??
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Diphenoxylate/atropine (Lomotil)- Antimotility- opiate class
MOA Uses Side Effects Contraindications
• acts on smooth
muscle of the
intestinal tract,
inhibiting GI
motility and
excessive GI
propulsion
• little to no
analgesic effect
• treatment of
diarrhea
• IBS diarrhea
• PO
2.5mg/0.025mg
atropine
• Can take
4x/day up to
20mg
• Prescription
• Drowsiness
• Confusion
• Constipation
• Risk for abuse
• Schedule V drug
• Interacts with MAOIs
(increases risk of HTN
crisis), CNS
depressants
• Children <6
• C.diff
Combined with atropine, which lowers risk for abuse (blocks some effects)
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Loperamide (Imodium)- Antimotility- opiate class
MOA Uses Side Effects Contraindications
• inhibits both
peristalsis in the
intestinal wall and
intestinal secretion,
thereby decreasing
the number of
stools and their
water content
• works on opioid
receptors
• treatment of
diarrhea
• IBS diarrhea
• Travelers
diarrhea
• PO
• 4mg initial dose
then 2mg after
each diarrheal
episode up to
16mg/day
• OTC
• Constipation
• Dry mouth
• Urinary retention
• Abdominal
cramps
• Ulcerative colitis
• Acute diarrhea from
C.diff, E.coli
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• How to choose an antidiarrheal??
o Severity of s/s and frequency
o Current medications being taken
o Cost of drug
o Loperamide does not have CNS effects like diphenoxylate/atropine
o Talk to MD
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Irritable Bowel Syndrome (IBS)
P: chronic intestinal discomfort
• Several different types depending on cause
• IBS with diarrhea (IBS-D); IBS with constipation (IBS-C) IBS with mixed (IBS-M)
• IBS-D is considered severe if the patient experiences one or more of the following:
(1) frequent and severe abdominal pain or discomfort, (2) frequent bowel urgency or
fecal incontinence, and (3) disability or restriction of daily activities because of IBS
L: abdominal pain/discomfort; changes in normal bowel habits (altering diarrhea and
constipation), gas, bloating; may have urgent sensation of needing to poop
A: bowel habits, any triggers (types of foods maybe), VS, medications, allergy testing
T: s/s; may get u/s of abdomen
T: no cure; symptom management; may take laxatives, fiber supplements, antidiarrheals;
surgical resection (colostomy, ileostomy likely)
o Alosteron- relaxes colon and slows waste movement through bowel
o Lubiprostone- increases fluid secretion in intestine to help with passing stools
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o Anti-inflammatory meds, antimotility agents, antimicrobials, immunotherapeutic
agents
E: Education on monitoring bowel habits and reporting any major changes (not having
BM for few days; increased diarrhea; severe abdominal cramps); symptom management;
diet modifications
Nursing implications for Anti-diarrheal
• Obtain thorough history of bowel patterns, general state of health, and recent history
of illness or dietary changes; assess for allergies
• Do not give bismuth subsalicylate to children or teenagers with chickenpox or
influenza because of the risk of Reye’s syndrome
• Use adsorbents carefully in older patients and those with decreased bleeding time,
clotting disorders, recent bowel surgery, or confusion
• Do not administer anticholinergics to patients with a history of narrow-angle
glaucoma, GI obstruction, myasthenia gravis, paralytic ileus, or toxic megacolon
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• Teach patients to take medications exactly as prescribed and to be aware of their
fluid intake and dietary changes.
• Assess fluid volume status, input and output, and mucous membranes before, during,
and after initiation of treatment
IBS drug management
• Drugs for IBS-D
• Alosetron (Lotronex)
• Rifaximin (Xifaxan)
• Eluxadoline (Viberzi)
• Drugs for IBS-C
• Lubiprostone (Amitiza)
• Linacotide (Linzess)
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Alosetron- IBS-D drug
MOA Uses Side Effects Contraindications
• selective blockade
of 5-HT3
receptors, which
are found
primarily on
neurons that
innervate the
viscera
• Treatment of
women with
IBS-D >6 mo
• Decrease
abdominal pain
• PO: usual dose:
0.5mg BID for
4 weeks, then
maybe 1mg for
4wks then stop
• Chronic
constipation
• Megacolon
• Ischemic colitis
• diverticulitis
• bowel obstruction
• ischemic colitis
• Interacts with
carbamazepine,
phenobarbital, cimetidine,
quinolone antibiotics,
ketoconazole,
clarithromycin,
voriconazole, and protease
inhibitors
23
Gastroesophageal Reflux Disease (GERD)
P: periodic flow of gastric contents into the esophagus due to lower esophageal sphincter
(LES) not closing all the way
• Can be due to a hiatal hernia; caffeine, alcohol, obesity, vomiting
L: heartburn, acid regurgitation, dysphagia, dry chronic cough, upper abdominal pain
after eating
A: PQRST of pain, s/s and when they occur, triggers
T: upper endoscopy; X-ray of upper GI tract; ambulatory acid probe test, esophageal
manometry
T: antacids, H2 receptor blockers (ex: Famotidine); proton pump inhibitors (ex:
omeprazole)
E: Educate that it increases risk of lung infections, Barrett’s esophagus, esophageal
strictures; eat small frequent meals, avoid certain foods (greasy, fatty, acidic, spicy,
caffeine, chocolate, alcohol); stop smoking; remain in upright position after eating
24
25
Peptic Ulcer Disease (PUD)
P: Gastric, esophageal, or duodenal ulcers that involve digestion of the GI mucosa by the
enzyme pepsin
• Parietal cells release hydrochloric acid after stimulated, which also makes chief cells
secrete pepsinogen
o Ulcers typically formed due to pepsin driving protein breakdown and
hydrochloric acid’s harsh effects
o Potential causes: Helicobacter pylori (H. pylori); stress-induced mucosal
damage, triggers for hydrochloric acids; harsh medications (NSAIDs),
Zollinger-Ellison Syndrome
L: (see gastric vs duodenal chart)
A: PQRST of pain and when it occurs (before meals? After meals?), s/s and when they
occur, triggers; bowel sounds; medication use; recent PO intake
T: blood or stool test; UREA breath test (for H. pylori); EGD; CT scan w/ contrast
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T: Proton pump inhibitors (PPIs), H2 receptor blockers, antibiotics if H.pylori; diet
modification; gastric resection; vagotomy
• Major indications for PPI or H2-receptor blockers: nasogastric (NG) tubes, placing
patients on ventilators, and others, predispose patients to bleeding of the GI tract.
Coagulopathy, a history of peptic ulcer or GI bleed, sepsis, use of steroids, ICU stay
of longer than 1 week, and occult bleeding are considered to indicate a high risk for
GI lesions
E: Educate on adequate diet and fluid intake; educate on med compliance
Gastric Ulcer Duodenal Ulcer
• Pain 1-2 hours post meal
• Weight loss
• Hemoptysis
• Pain occurs on empty stomach
• Pain in middle of the night
• Black tarry stools
27
Deeper look at Helicobacter pylori (H. pylori)
• TX: PPIs like Pantoprazole; ABX like Metronidazole
• gram-negative bacillus that can colonize the stomach and duodenum
• sneaks between epithelial cells so it can survive the acid and pepsin
o can live there for decades
• big cause of PUD- found that 60-75% pts with PUD have H.pylori; duodenal ulcers
more common in pts with this; removing H.pylori helps with ulcer healing and
decreases reoccurrence
o likely possibilities include enzymatic degradation of the protective mucus layer,
elaboration of a cytotoxin that injures mucosal cells, and infiltration of
neutrophils and other inflammatory cells in response to the bacterium’s presence
• H.pylori produces urease that forms CO2, ammonia
• Tends to promote gastric cancer
• DX: biopsy; serologic, breath(measures CO2), stool samples
28
29
30
Stress ulcers (from module 12)
• result from severe trauma, such as burns or head injury, serious systemic problems like
hemorrhage or sepsis
• Ischemic ulcers- occur within hours of trauma, burns, hemorrhage, heart failure, or
sepsis
• Curling ulcers- ulcers that develop due to burn injury
• Cushing ulcers- ulcers that develop due to a brain injury or brain surgery
o Increased vagal stimulation of acid secretion may occur
• First indicator of stress ulcers is usually hemorrhage because of the rapid onset and
masking by the primary problem
• Prophylaxis with H2 receptor blockers, PPIs
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Antacids
• Ex: Sodium bicarbonate, aluminum hydroxide, aluminum and magnesium hydroxide
(Maalox), calcium carbonate (Tums), Magnesium hydroxide (M.O.M)
• Basic compounds used to neutralize stomach acid
• Contain salts of aluminum, magnesium, calcium, and/or sodium
• Many antacid preparations also contain the anti-flatulent drug Simethicone
• Many aluminum- and calcium-based formulations have magnesium for acid-
neutralizing and counteracting constipation from aluminum and calcium
• Avoid magnesium containing antacids in renal failure
• Calcium carbonate increases risk of renal stones
• Many drug interactions (see table 50.1 picture)
• OTC meds- capsules, tablets, powders, chewable, suspensions
*The following chart is to show the basic of how to look at overall drug class*:
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*Prostaglandins in the stomach work to prevent histamine from binding to receptor cells and from preventing cAMP
MOA: reduce acid
- neutrolize gastric acid
- promote mucosal defense by promoting mucus
secretion, *prostaglandins, bicarbonate
Side Effects:
-Mg: diarrhea
-Al+Ca: constipation
-Ca: renal stones, rebound hyeracidity ; milk-alkali
syndrome
-Bicarb: alkalosis (in high doses)
Al: can cause hypercalcemia
Examples:
-sodium bicarbonate
-aluminum hydroxide
-calcium carbonate
-magnesium hydroxide
Contraindications:
-Severe renal failure, GI obstruction
-**Many drug interactions
Interventions:
-administer 1-2 hours before/after other drugs
-educate on adequate dosing and preventing overuse
-administer with 8oz water
Antacids
33
**
34
Histamine H2-Receptor Blockers (H1-receptor blockers are a thing, but work more
with allergies )
• Ex: Famotidine (PO, IV) , Cimetidine, (PO, IV, IM), Nizatidine (PO)
o OTC except for Nizatidine
• Used to treat gastric and duodenal ulcers, GERD, Zollinger-Ellison syndrome, stress-
induced ulcer prevention, sour stomach
• MOA: block the histamines from binding to H2 receptors from binding and causing
gastric acid secretion (This is why I say to read the drug class name backwards...
blocks Histamine and H2-receptors, may make it more memorable)
• Contraindications: pregnancy, breastfeeding, age <16
• Interactions: antacids (at least at the same time)
• AE: confusion, headache, diarrhea, hypotension, abdominal cramps, jaundice
35
Famotidine (Pepcid)- H2-Receptor Blocker
MOA Uses Side Effects Contraindications
• Binds to H2
receptors within
parietal cells in
stomach to obstruct
histamine actions
Info for this chart is
from:
*Famotidine - StatPearls - NCBI Bookshelf*
• Dyspepsia
• Heartburn
• Ulcers
• Reduction of
gastric acid
• PO: 10-20 mg
BID; 40mg
daily
• IV
• Headache
• Dizziness
• Diarrhea
• Constipation
• Confusion
• Increased risk for
PNA
• Swallowing difficulties
• Hematemesis, melena
• Pregnancy,
breastfeeding
36
Proton Pump Inhibitors (PPIs)
• Ex: Omeprazole, Pantoprazole, Lansoprazole, Esomeprazole
• Block the proton pumps from transporting hydrogen
o Bind to hydrogen-potassium ATPase enzyme that typically work to increase
gastric acid= lower gastric acid
• Uses: GERD, Zollinger-Ellison syndrome, H. pylori induced ulcers, ulcer
prophylaxis, short term PUD, NSAID-induced ulcers, gastric protection in critical
care settings/use of NG tubes
• AE: risk for C.diff, osteoporosis, pneumonia, hypomagnesemia
o Risk for dementia and SLE???
• Risk for achlorhydria as PPIs block about 90% of gastric acid secretion in 24-hour
period
o Can increase risk of infections
37
Omeprazole- PPI
MOA Uses Side Effects Contraindications
• Converts to action
form in parietal
cells to inhibit H,
K, ATP/proton
pump to block
gastric acid
formation
• Esophagitis
• Duodenal ulcer
• GERD
• Failed therapy
from H2 receptor
blockers
• PO- 20-40mg BID
• Often taken 30-60
minutes AC
• Risk for fractures,
osteoporosis,
PNA, C.diff
• Hypomagnesemia
• Achlorhydria
• Interact with clopidogrel
(reduce effects of
clopidogrel)
• Severe liver impairment
38
Pantoprazole- Proton Pump Inhibitor
MOA Uses Adverse Effects Contraindications
• Converts to action
form in parietal
cells to inhibit H,
K, ATP/proton
pump to block
gastric acid
formation
• prodrug
• GERD
• PUD
• Zollinger-
Ellison
syndrome
• H.pylori
• PO- delayed
release,
granules*
• IV
• May increase risk
of C.diff
• Headache
• Abdominal pain
• Joint pain
• Liver impairment
• Pregnancy, breastfeeding
• Osteoporosis
o Increases risk of
osteoporosis!
• Interacts with warfarin,
digoxin, methotrexate,
clopidogrel
• Caffeine, alcohol, iron
• Take 2 hours apart from
antacids
*Caution with granules and NG tube- NG MUST be 16fr or bigger to prevent clogging*
39
Sucralfate (Carafate)- gastroduodenal protector
MOA Uses Side Effects Contraindications
• Absorbs pepsin in
stomach to decrease
its amount
• Lines the stomach to
help prevent ulcers
• On wounds/tissue:
binds to epidermal
growth and helps
promote tissue growth
*Sucralfate - StatPearls - NCBI
Bookshelf *
• Duodenal ulcers
• Dyspepsia
• GERD
• Stress ulcer
prevention
• CKD as it binds
to phosphate
• PO, rectal
• Topical
(typically to
help with skin
wounds,
mucosal ulcers)
• Hyperglycemia
• Dry mouth
• Headache
• Pruritis
• Hypophosphatemia
• Hepatic and renal
impairment
• Pregnancy
• Interacts with
naproxen, potassium
phosphate
• May impair
absorption of other
drugs
40
Simethicone- Anti-flatulent
MOA Uses Side Effects Contraindications
• Decreases gas
bubbles that lead to
flatulence but do
not decrease gas
production
• Flatulence and
bloating
management
• May be used
for H.pylori
• Mild diarrhea
• Nausea
• Renal stones
• ETOH
• May decrease
absorption of digoxin,
ciprofloxacin
41
42
43
Vomiting Center
• Area in brain responsible for N/V initiation
• How the vomiting reflex makes us throw up:
o Taking a deep breath Closing the glottis and raising the soft palate Ceasing
respiration (minimizes risk of aspiration of vomitus into the lungs, where it may
cause significant inflammation and obstruction of the airways) Relaxing the
gastroesophageal sphincter Contracting the abdominal muscles(which
squeezes the stomach against the diaphragm and forces the gastric contents
upward and out of the mouth) Promoting expulsion of the contents of the
stomach by reverse peristaltic waves in the proximal duodenum and antrum
o Color matters
▪ Hematemesis- bloody vomit
• May appear brown; “coffee-ground emesis”
▪ Yellow- usually bile from duodenum
▪ Brown- bile from lower intestine
44
45
Antiemetics and Antinausea Meds
• Drugs used to relieve N/V
• 7 different subclasses; All work on the same sites in the vomiting reflex pathways,
but their MOAs differ
• NTs involved in N/V: ACh, histamine, serotonin, prostaglandins, dopamine
(Table 52.2 with the 7 different subclasses for antiemetics)
46
(table 52.3)
• Anticholinergics
o Ex: Scopolamine
o Bind to and block ACh receptors in the inner ear labyrinth; Block transmission
of nauseating stimuli to CTZ; Also block transmission of nauseating stimuli
from the reticular formation to the VC
47
• Antihistamines
o Ex: Meclizine, dimenhydrinate, diphenhydramine
o Inhibit ACh by binding to H1 receptors; Prevent cholinergic stimulation in
vestibular and reticular areas
o Uses: motion sickness, nonproductive cough, allergy symptoms, sedation
o Interventions: Baseline VS; monitor for dehydration with severe vomiting;
monitor for hypotension and tachycardia; Monitor bowel sounds for
hypoactivity or hyperactivity; Assess urinalysis before and during therapy
48
Meclizine-Antihistamine
MOA Uses Side Effects Contraindications
• blocks H1 receptors
in chemoreceptor
trigger zone
• has anticholinergic
effects
• Motion
sickness
prophylactic
• Vertigo
• PO 25-50mg 1
hour prior to
travel; 25-
100mg/day 1-
4 doses for
vertigo
• Dizziness
• Drowsy
• Urinary retention
• Blurred vision
• Dry mouth
• Caution with asthma,
hepatic and renal
impairment, glaucoma
• Interactions with:
CNS depressants (may
increase depressant
effect)
• Pregnancy
49
• Serotonin blockers
o Ex: Ondansetron (Zofran)
o Block serotonin receptors in the GI tract, CTZ, and VC
o Uses: N/V in patients receiving chemotherapy and postop
50
Ondansetron (Zofran)-Serotonin Receptor Antagonist
MOA Uses Side Effects Contraindications
• Blocks serotonin
receptors in
chemotherapy trigger
zone and vagal neurons
in GI tract
• N/V prevention
• Chemotherapy
induced N/V,
radiation,
anesthesia
• Morning sickness
for pregnancy
(with caution)
• PO 8mg
• IV 4mg
• Headache
• Diarrhea
• Dizziness
• **prolonged QT
interval on cardiac
monitoring (can cause
deadly arrythmias)
• SJS
• Hx of Torsade’s de pointes
(arrhythmia)
• Caution in pregnancy, breast
feeding
• Caution with QT
prolongation
• Interactions: metformin
(increase blood
concentration)
• Most effective if combined used with dexamethasone
51
• Prokinetics
o Ex: Metoclopramide (Reglan)
o Block dopamine receptors in the CTZ and cause CTZ to be desensitized to
impulses it receives from the gastrointestinal (GI) tract
o Also stimulate peristalsis in GI tract, enhancing emptying of stomach contents
52
Metoclopramide (Reglan)- Prokinetic
MOA Uses Adverse Effects Contraindications
•Suppresses emesis
through blockade of
dopamine receptors in
chemoreceptor trigger
zone
•Increases gastric
motility (peristalsis)
by enhancing
acetylcholine actions
• Chemo-induced
N/V; post op
N/V; pregnancy
N/V
• Can be used for
hiccups
• PO
• IV 1-2 mg/kg
• High doses may
cause sedation and
diarrhea
• Long-term high
dose can lead to
tardive dyskinesia
• Drug allergy
• Bowel obstructions
53
• Tetrahydrocannabinoids (THC)
o Ex: Dronabinol, Nabilone
o Used for chemotherapy induced N/V
o Major psychoactive substance in marijuana
o Inhibitory effects on reticular formation, thalamus, cerebral cortex
o Alter mood and body’s perception of its surroundings, which may help relieve
nausea and vomiting
54
Dronabinol- Cannabinoid
MOA Uses Adverse Effects Contraindications
• Exact MOA unknown
• May bind to
cannabinoid receptors
near vomiting center
• N/V not
responsive to
other drug
therapy
• Chemotherapy
induced N/V
• PO
• Dissociation
• Drowsiness
• Tachycardia
• Hypotension
• **Risk for
dependence-
Schedule III drug
• Drug allergy
• Caution with substance abuse,
seizures
• Interact with Warfarin
(increase concentration in
blood); CNS depressants
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• Neurokinin blockers
o Ex: aprepitant
o Blocks neurokinin1-type receptors in chemoreceptor trigger zone.
o Uses: prevent postop N/V, chemo-induced N/V
• Herbal products: Used for nausea and vomiting, including that caused by
chemotherapy, morning sickness, and motion sickness
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Apreptinant-Neurokinin1 Antagonist
MOA Uses Side Effects Contraindications
• blocks H1 receptors
in chemoreceptor
trigger zone
• has anticholinergic
effects
• Postop N/V
prevention,
chemo
• PO
• Peak drug level
4 hours
• Urticaria
• Thrombocytopenia
• DVT
• Caution with hepatic
impairment, pregnancy
• May increase
metabolism of Warfarin;
may decrease effect of
oral contraceptives
• Alters hepatic enzymes
so caution with
Diltiazem, antifungals
• May increase effects of
glucocorticoids
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• Antidopaminergics
o Prochlorperazine, Promethazine
o Block dopamine receptors in the CTZ
o Uses: psychotic disorders, intractable hiccups
o Prochlorperazine (Compazine) is an antiemetic AND antipsychotic
▪ Patients may build dependence on this med
▪ Used for N/V, anxiety, schizophrenia
• AE: Anorexia, nausea and vomiting, skin reactions
• May increase absorption of oral medications
• Increase bleeding risk with anticoagulants
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Promethazine (Phenergan)-Dopamine Antagonist
MOA Uses Adverse Effects Contraindications
• Blocks dopamine2
receptors at
chemoreceptor trigger
zone
• Also has
antihistamine effects
• Chemo-induced
N/V
• Postop N/V
• Pancreatitis
• PO, IV, IM
12.5-25mg 4-6
hours
• Rectal
• Dizziness
• Drowsiness
• Tachycardia
• Thrombocytopenia
• Dry mouth
• Blurry vision
• Extrapyramidal
effects
• QT prolongation
• BBW: IV use may
cause tissue
necrosis
• Drug allergy
• Breastfeeding
• Myelosuppression
• Reye’s syndrome
• Children <2 (d/t resp
suppression; paradoxical-
CNS stimulation)
• Caution with pregnancy,
seizures, CNS depression
• Interacts with CNS
depressants
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• Caution with IV administration
o Assess and flush IV before administering drug (no duh... this is for every IV
administration)
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PEDIATRICS
Esophageal Atresia
• Congenital anomaly where esophagus is not fully developed
• Different classes depending on where it occurs and what it affects
• *May have trouble with NG tube placement if needed due to change in anatomy
• S/S: coughing, choking, cyanosis; resp distress, gagging
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Infantile Hypertrophic Pyloric Stenosis
• Acquired narrowing and distal obstruction of the pylorus
• Unclear etiology—likely genetic and environmental factors
• Forceful, nonbilious vomiting starting 2-8 weeks after birth
• Vomiting causes weight loss, electrolyte imbalances, and dehydration
• Infant irritable because of hunger and esophageal discomfort
• Evaluation and treatment: hypertrophic pylorus is palpable in the RUQ
• Standard treatment is pyloromyotomy
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Intestinal obstructions
• Duodenal obstruction
• Upper abdominal distention, visible peristaltic waves, decrease in meconium
stools, weight loss, persistent vomiting, and dehydration
• Obstruction may be partial or complete
• “Double bubble” sign
• Jejunal and ilial obstruction
• Atresia, stenosis, megacolon, intussusception, Meckel diverticulum, intestinal
duplication, or strangulated hernia
• Malrotation- Small intestine lacks normal posterior attachment
• Volvulus- part of intestine twists upon itself
o Medical emergency!!
o Blood flow is obstructed= ischemia, necrosis
o Surgery required to untwist bowels
o Does not just occur in babies, but older age too
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o Common causes: chronic constipation, high fiber diets
o DX: X-ray
o Infants S/S: sudden vomiting, abdominal distention and tenderness,
hematochezia, fever, crying, pain
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Hirschsprung Disease (aganglionic megacolon)
• Caused by the failure of the parasympathetic nervous system to form intramural
ganglion cells in the enteric nerve plexuses
• Abnormally innervated colon impairs fecal movements
• Causes colon distention
• S/S: Mild to severe constipation, diarrhea, enterocolitis, sepsis, death
• Surgery is the definitive treatment
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Anorectal Malformations
• Anorectal stenosis, imperforate anus, anorectal atresia, and rectal atresia
• 40% of infants born with anorectal malformations have other developmental anomalies
• Most identified in routine physical examination
• Treated with dilations for stenosis or surgery for other malformations
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Intussusception
• Telescoping of a proximal segment of intestine into a distal segment, causing an
obstruction
• The most common scenario is the ileum telescopes into the cecum and part of the
ascending colon by collapsing through the ileocecal valve
• Causes ischemia and necrosis if not treated
• s/s: abdominal pain, irritability, vomiting, and “currant jelly” stools
• Evaluation and treatment
• ultrasonography
• Reduction with enema
• Surgical reduction
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Celiac Disease
• Gluten is the protein component in cereal grains (wheat, rye, barley, malt)
• caused by dietary, genetic, and immunologic factors
• Defect in intestinal enzyme prevents further digestion of gliadin (breakdown product of
gluten)
• Onset of manifestations depends on the age of the infant when gluten-containing
substances are added to the diet
• Usually by 18 months
• Severity of symptoms varies tremendously
• Can occur in middle-aged adults
• Celiac crisis results in severe diarrhea, dehydration, malabsorption, and protein loss
• Diagnosis confirmed with serologic autoantibody measurement
• Toxic effect on intestinal villi—atrophy of villi
• Malabsorption and malnutrition result
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• s/s: Steatorrhea, muscle wasting, failure to gain weight, irritability and malaise
common
• First signs appear when cereals are added (At about 4 to 6 months of age)
• Treatment is a gluten-restrictive diet, and vitamin D, iron, and folic acid supplements
or diet increases are given
• Intestinal mucosa returns to normal after a few weeks without gluten intake
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Failure to Thrive (FTT)
• Also called growth faltering
• Characterized by inadequate physical development of an infant or child
• Deceleration in weight gain
• Low weight/height ratio or BMI ratio
• Low weight/height/head circumference ratio
• Also very common in adults
• Multifactorial
• Biologic
• Psychosocial
• Environmental
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Necrotizing Enterocolitis
• Ischemic, inflammatory condition that causes bowel necrosis and perforation
• Most common severe neonatal gastrointestinal emergency
• Primarily affects smallest and most premature infants
• Etiology unclear
• Risk: factors: infections, abnormal bacterial colonization, intestinal ischemia, immature
immunity, exaggerated inflammatory responses, immature intestinal motility and
barrier function, perinatal stress, effects of medications and feeding practices, genetic
predisposition
• Clinical manifestations
• Mild abdominal distention to bowel perforation
• Bloody stools and septicemia
• Evaluation and treatment
• Clinical manifestations, laboratory results, and plain films of abdomen
• Cessation of feeding, gastric suction, antibiotics, and surgery
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Diarrhea management for children
• Keep child home if having diarrhea, or really any sign of infection
o Sharing is caring, but not in circumstances like this
• Monitor skin
o Apply barrier cream
o Thorough cleaning
• Monitor I+Os
o How many diaper changes? How many diarrheal episodes
• Like diarrhea in adults... encourage frequent intake fluids and electrolytes
o Maybe try small bites/sips
o Pedialyte