Pharmacology
Pharmacology
Drugs
Drugs that
that Affect
Affect the
the
Gastrointestinal
Gastrointestinal System
System
Topics
Topics
••
••
••
••
••
Peptic
Peptic Ulcer
Ulcer Disease
Disease
Constipation
Constipation
Diarrhea
Diarrhea
Emesis
Emesis
Digestion
Digestion
Peptic
Peptic Ulcer
Ulcer Disease
Disease
Factors
Factors that
that
Increase
Increase Acidity
Acidity
Factors
Factors that
that
Protect
Protect Against
Against
Acidity
Acidity
Peptic
Peptic Ulcer
Ulcer Disease
Disease
•• Factors
Factors Increasing
Increasing
–– H.
H.pylori
pylori
–– NSAIDs
NSAIDs
–– Acidic
Acidicagents
agents
–– Pepsin
Pepsin
–– Smoking
Smoking
•• Factors
Factors Decreasing
Decreasing
–– Mucus
Mucusproduction
production
–– Buffers
Buffers
–– Blood
Bloodflow
flow
–– Prostaglandins
Prostaglandins
Regulation
Regulation of
of Gastric
Gastric Acid
Acid
Secretion
Secretion
H
H22 Receptor
Receptor Antagonists
Antagonists
••
••
••
••
••
••
Inhibits
Inhibits gastric
gastric acid
acid secretion
secretion
No
No effect
effect on
on H
H11 receptors
receptors
®®)
cimetidine
(Tagamet
cimetidine (Tagamet )
®®)
ranitidine
(Zantac
ranitidine (Zantac )
®®)
famotidine
(Pepcid
famotidine (Pepcid )
®®)
nizatidine
(Axid
nizatidine (Axid )
H
H22 Receptor
Receptor Antagonists
Antagonists
•• Indications:
Indications:
–– PUD
PUD
–– GERD
GERD
–– Prevention
Prevention of
of aspiration
aspiration pneumonia
pneumonia
Proton
Proton Pump
Pump Inhibitors
Inhibitors
••
••
++H++ATPase (Proton Pump)
K
K H ATPase (Proton Pump)
Irreversible
Irreversible inhibition
inhibition
–– Must
Must synthesize
synthesize new
new enzyme
enzyme
–– Long
Long duration
duration
••
••
®®)
omeprazole
(Prilosec
omeprazole (Prilosec )
®®)
lansoprazole
(Prevacid
lansoprazole (Prevacid )
Anticholinergics
Anticholinergics
••
••
®®)
pirenzepine
(Gastrozepine
pirenzepine (Gastrozepine )
Other
Other anticholinergics
anticholinergics have
have too
too many
many side
side
effects
effects and
and are
are not
not used
used
Prostaglandin
Prostaglandin Analog
Analog
®®)
•• misoprostol
(Cytotec
misoprostol (Cytotec )
–– Approved
Approved for
for treating
treating PUD
PUD due
due to
to long
long term
term
NSAID
NSAID use
use
Antacids
Antacids
••
••
Increase
Increase pH
pH of
of gastric
gastric environment
environment
Hydroxides
Hydroxides
–– Aluminum
Aluminum
–– Magnesium
Magnesium
•• Carbonates
Carbonates
–– Calcium
Calcium
Antacids
Antacids
•• Most
Most OTC
OTC drugs
drugs are
are combinations
combinations
–– DiGel
DiGel®®
–– Amphojel
Amphojel®®
–– Maalox
Maalox®®
–– Milk
Milk of
of Magnesia
Magnesia®®
–– Mylanta
Mylanta®®
Antibiotics
Antibiotics
••
••
••
••
••
Aimed
Aimed at
at eliminating
eliminating H.
H. pylori
pylori
®®)
bismuth
(Pepto-Bismol
bismuth (Pepto-Bismol )
®®)
metronidazole
(Flagyl
metronidazole (Flagyl )
®®)
amoxicillin
(Amoxil
amoxicillin (Amoxil )
®®)
tetracycline
(Achromycin
V
tetracycline (Achromycin V )
Stool
Stool Formation
Formation
Water
Water absorbed
absorbed in
in colon
colon (~90%)
(~90%)
–– Excessive
Excessive absorption
absorption
•• Constipation:
Constipation:hard,
hard,dehydrated
dehydratedstool
stool
•• Increases
Increasesstrain
strainon
ondefecation
defecation
•• Harmful
Harmfulfor
forsubset
subsetof
ofpatients
patients
–– Recent
Recentepisiotomy,
episiotomy,colostomy,
colostomy,hemorrhoids,
hemorrhoids,
cardiovascular
cardiovasculardisease
disease
–– Inadequate
Inadequate absorption
absorption
•• Diarrhea:
Diarrhea:soft,
soft,non-formed,
non-formed,liquid
liquidstool
stool
Terms
Terms
Laxative
Laxative
Production
Production of
of soft,
soft, formed
formed
stool
stool over
over 11 or
or more
more days
days
Cathartic
Cathartic
Rapid,
Rapid, intense
intense fluid
fluid evacuation
evacuation
of
of bowel.
bowel.
Laxatives
Laxatives
••
••
••
••
Bulk
Bulk forming
forming
Surfactants
Surfactants
Stimulants
Stimulants
Osmotics
Osmotics
Bulk
Bulk Forming
Forming Laxatives
Laxatives
••
••
Absorb
Absorb water
water
Soften
Soften and
and enlarge
enlarge
stool
stool
•• Fecal
Fecal swelling
swelling
promotes
promotes peristalsis
peristalsis
•• methylcellulose
methylcellulose
(Citrucel
(Citrucel®®))
•• psyllium
psyllium
®®)
(Metamucil
(Metamucil )
•• Polycarbophil
Polycarbophil
Surfanctant
Surfanctant Laxatives
Laxatives
•• Lowers
Lowers surface
surface
tension
tension
–– Facilitates
Facilitateswater
water
penetration
penetration
•• Docusate
Docusate salts
salts
®®
–– Colace
Colace
®
–– Modane
ModaneSoft
Soft®))
Stimulant
Stimulant Laxatives
Laxatives
••
••
Stimulate
Stimulate peristalsis
peristalsis
Increases
Increases water
water and
and
electrolytes
electrolytes secretion
secretion
into
into intestinal
intestinal lumen
lumen
•• Decreases
Decreases water
water and
and
electrolyte
electrolyte
reabsorption
reabsorption
•• Phenylolpthalein
Phenylolpthalein
®®, Feen-a–– (Ex-Lax
(Ex-Lax , Feen-a®
®
Mint
Mint®,,Correctol
Correctol®))
®®)
•• bisacodyl
(Ducolax
bisacodyl (Ducolax )
Osmotic
Osmotic Laxatives
Laxatives
•• Poorly
Poorly absorbed
absorbed salts
salts
remain
remain in
in fecal
fecal matter
matter
•• Pull
Pull water
water into
into lumen
lumen
•• Magnesium
Magnesium hydroxid
hydroxid
(Milk
(Milk of
of Magnesia®)
Magnesia®)
Antidiarrheal
Antidiarrheal
•• Diarrhea
Diarrhea isis usually
usually aa compensatory
compensatory
action…
action…
–– Treatment
Treatment aimed
aimed at
at cause,
cause, no
no symptom
symptom
•• Opioid
Opioid receptors
receptors in
in GI
GI tract
tract decrease
decrease
motility
motility
–– Increase
Increase time
time for
for water
water reabsorbtion
reabsorbtion
Antidiarrheal
Antidiarrheal Agents
Agents
••
••
••
••
paregoric/opium
paregoric/opium tincture
tincture
®®)
diphenoxylate
(Lomotil
diphenoxylate (Lomotil )
®®)
defenoxin
(Motofen
defenoxin (Motofen )
®®)
loperamide
(Imodium
loperamide (Imodium )
Vomiting
Vomiting Stimulus
Stimulus
Antiemetics
Antiemetics
••
••
••
••
Serotonin
Serotonin (5HT)
(5HT) Antagonists
Antagonists
Dopamine
Dopamine (DA)
(DA) Antagonists
Antagonists
Anticholinergics
Anticholinergics (muscarinic
(muscarinic blockers)
blockers)
Cannabinoids
Cannabinoids
Serotonin
Serotonin Antagonists
Antagonists
•• Used
Used to
to treat
treat side
side effects
effects of
of chemotherapychemotherapyinduced
induced emesis
emesis
®®)
•• condansetron
(Zofran
condansetron (Zofran )
•• Doesn’t
Doesn’t affect
affect dopamine
dopamine receptors
receptors
–– ∴
∴ no
no extrapyramidal
extrapyramidal effects
effects
•• Granisetron
Granisetron (Kytril®)
(Kytril®)
Dopamine
Dopamine Antagonists
Antagonists
•• Phenothiazines
Phenothiazines
–– prochloraperazine
prochloraperazine (Compazine®)
(Compazine®)
–– promethazine
promethazine (Phenergan®)
(Phenergan®)
•• Butyrophenones
Butyrophenones
®®)
–– haloperidol
(Haldol
haloperidol (Haldol )
®®)
–– droperidol
(Inapsine
droperidol (Inapsine )
®®)
•• metoclopramide
(Reglan
metoclopramide (Reglan )
Cannabinoids
Cannabinoids
•• Tetrahydrocannabinol
Tetrahydrocannabinol (THC)
(THC)
–– Active
Active ingredient
ingredient in
in marijuana
marijuana
–– Dronabinol
Dronabinol (Marinol
(Marinol®®))
–– Nabilone
Nabilone (Cesamet
(Cesamet®®))
Digestion
Digestion Aids
Aids
•• Useful
Useful for
for inactive
inactive vagal
vagal stimulus/bypassed
stimulus/bypassed
duodenum
duodenum
®®)
•• Pancreatin
(Entozyme
Pancreatin (Entozyme )
®®)
•• Pancrelipase
(Viokase
Pancrelipase (Viokase )
Thank
Thank You!
You!
•• To
To Temple
Temple College
College EMS
EMS Professions
Professions for
for
permission
permission to
to use
use their
their materials
materials