GIT (Acid-Peptic Diseases) Flashcards
Drugs used for peptic acid disease
Proton Pump Inhibitors
Antacids
Mucosal protective agents
H2 Blockers
Antibiotics
Motility promoters
Motilin agonists, antidiarrheals, Dopamine antagonists, laxatives,
Drugs for irritable bowel disease
Chloride Channel activators, antispasmodics, serotonin inhibitors
Drugs for inflammatory bowel disease
Corticosteroids immunosuppresants, anti-tnf drugs, 5-asa drugs
Other agents
Pancreatic lipase, Antidiarrheal ursodiol, laxatives
antiemetics
neurkinin receptor, cannabinoids, corticosteroids, antimuscarinic, h1 blockers, d2 blockers, 5 ht3 blockers
Acid– peptic disease includes:
Gastroesophageal Reflux
Peptic ulcer (gastric or duodenal)
Stress related injury
Gastroesophageal Reflux refers to
Heart burn
Heart burn occurs when acid rise to the
esophagus
T/F: The location of HB and Angina are the same and
but the pain felt are different
T
heat sensation rising
Heartburn
suffocating/ crushing feeling
Angina
The higher the stress, the ________(higher/lower) the secretion of
acid
higher
Acid-Peptic Disease is the mucosal erosion or ulceration due to the caustic effect of ______, ______, and ______
acid, pepsin and bile
Peptic ulcer may also be dueto the presence of
Helicobacter pyroli
Prolong use of NSAIDs can lead to formation of ______
gastric
ulcer
Simplest drug used in acid peptic disease
ANTACID
ANTACIDs are ______ bases that react with the gastric HCl
weak bases
Principal mechanism of Antacid
reduction of the intragastric
acidity
For Antacids, a single dose of _______ mEq of antacid given _______ after meal
effectively neutralizes gastric acid for up to __________
156; 1 hour; 2 hours
Antacids may affect the absorption of other medications by __________ or ________
binding
the drug or altering the intragastric pH
Baking soda, Alka seltzer
SODIUM BICARBONATE
SODIUM BICARBONATE produces
CO2 and NaCl
In Sodium bicarbonate, unreacted alkali is readily absorbed which could lead to
_______________
metabolic alkalosis
exacerbate fluid retention
Sodium chloride
ADR of NaHCO3
○ Flatulence
○ Bloating
○ Belching
Tums
CaCO3
Less soluble and reacts slowly than sodium bicarbonate
CaCO3
CaCO3 forms
CaCl2 and CO2
Excessive dose of CaCO3 could lead to
hypercalcemia, renal
insufficiency and metabolic alkalosis
MgOH/AlOH reacts slowly to
HCl
Unabsorbed magnesium salt may cause
osmotic diarrhea
Unabsorbed aluminum salt
constipation
Commonly administered together to minimize impact on
bowel function
MgOH/AlOH
MgOH/AlOH is absorbed and excreted by the __________ thus should not be
taken in long term by patients with __________
kidney; renal insufficiency
-tidine drugs
HISTAMINE 2 RECEPTOR ANTAGONIST
Introduced in the 1970s
H2 antagonist
H2 antagonist drugs
Cimetidine, Ranitidine, Famotidine and Nizatidine
blocks histamine at the H2 receptor gastric parietal cells
H2 antagonist
H2 antagonists are rapidly absorbed from the
intestine
Mainstay drug in APD
H2 antagonist
Inhibits stomach acid production, especially at night
H2 antagonist
H2 antagonists that undergo first pass
hepatic resulting to a bioavailability of approximately 50%
Cimetidine, Ranitidine and Famotidine
H2 antagonist that has little first pass metabolism
Nizatidine
H2 antagonist is cleared bya combination of__________, __________, ____________
a combination of hepatic metabolism,
glomerular filtration and renal tubular secretion
H2 antagonist reduces acid secretion stimulated by histamine as well as ___________, and _________ agents by 2 mechanisms
gastrin and cholinomimetic
2 mechanisms involved in the reduction of acid secretion by H2 Antagonist
-Histamine release from ________ by ________ stimulation blocked from binding to the parietal cell H2 receptor
-____________of the parietal cell by gastrin or acetylcholine has a ____________ on acid secretion in the presence of H2 receptor blockade
-Histamine release from ECL cells by gastrin or vagal stimulation blocked from binding to the parietal cell H2 receptor
-Direct stimulation of the parietal cell by gastrin or acetylcholine has a diminished effect on acid secretion in the presence of H2 receptor blockade
When given in usual prescription doses, all inhibit 60 – 70
% of total 24-hour acid secretion.
H2 Antagonist
Clinical uses of H2 Antagonists
○ GERD
○ PUD
○ Non-ulcer dyspepsia
○ prevention of bleeding from stress-related gastritis
T/F: H2 Antagonists are extremely safe drugs
T
T/F: H2 Antagonists rarely causes ADR
T - Occur in less than 3%: diarrhea, headache, fatigue,
myalgias and constipation
this may increase
the risk of nosocomial pneumonia in critically ill patients
IV H2 blocker of PPI
All except _________ inhibit gastric first pass metabolism
of ethanol, especially in women
famotidine
Cimetidine inhibits binding of ____________ to androgen
receptor, inhibits metabolism of _________ and increase
___________ levels
dihydrotestosterone; estradiol; serum prolactin levels
Long term or high dose may cause impotence
Cimetidine
impotence in men
Gynecomastia
impotence in women
Galactorrhea
CIMETIDINE interferes with several important ________________________
drug metabolism pathway
hepatic cytochrome P450
Half-lives of drugs metabolized by the pathways may be
prolonged
CIMETIDINE
Compete with creatinine and certain drugs for renal
tubular secretion
CIMETIDINE
-prazole drugs
PROTON PUMP INHIBITOR (PPI)
PROTON PUMP INHIBITOR (PPI) DRUGS
Omepazole, Esomeprazole, Lansoprazole, Dexlansoprazole,
Rabeprazole and Pantoprazole
PPI is a substituted ___________ that resembles H2 antagonist
benzimidazole
to protect the acid labile prodrug
formulated for delayed release as acid resistant, enteric
coated capsule or tablet
Inactivate prodrug
T/F: PPI must be inactivated to protect the acid labile prodrug
formulated for delayed release as acid resistant, enteric
coated capsule or tablet
T
T/F: PPI drugs are mostly modified release
T
Lipophilic weak base (pKa 4 to 5), and after intestinal
absorption, diffuses readily across lipid membrane into
acidified compartment
PPI
Irreversibly inactivate the H+/K+ ATPase pump
PPI
Rapidly metabolized PPI may require ______________ to have an
effect
3 – 4 days
PPI must be administered with food or without food?
Without food
inhibits both fasting and meal stimulated secretion
because they block the final common pathway of acid
secretion
PPI
Preferred to use than H2 blockers
PPI
at Standard doses, inhibits 90 to 98% of 24-hour acid
secretion
PPI
Chronic treatment for hypergastrinemia
PPI
Minor reduction in _______
occur during proton pump inhibition
oral cyanocobalamin absorption
May cause Respiratory and enteric infection
PPI
T/F: Decreased gastric acidity may alter absorption of drug
which intragastric acidity affect drug bioavailability
T
All PPI are metabolized by
hepatic P450 cytochrome
T/F: Because of its short half-lives PPI interaction are rare
T
PPI that inhibits metabolism of warfarin,
diazepam and phenytoin
Omeprazole
PPI that decreases metabolism of diazepam
Esomeprazole
PPI that enhances clearance of theophylline
Lansoprazole
PPI that has no significant drug
interaction
Rabeprazole and Pantoprazole
important in
stimulating mucus and bicarbonate secretion and mucosal
blood flow
Mucosal prostaglandins
MUCOSAL PROTECTIVE AGENTs
Sucralfate
Misoprostol
Bismuth Compound
Salt of sucrose complexed to sulfurated aluminum
hydroxide
SUCRALFATE
In water or acidic solution, it forms a viscous, tenacious
paste that binds selectively to ulcer or erosion for up to 6
hours
SUCRALFATE
Is sucralfate soluble or poorly soluble
Poorly soluble molecule
binds to injured tissue in the stomach
Sucralfate
(Sucralfate) Negatively charged sucrose binds to the positively charged
protein in the base of ulcer or erosion, forming a ___________________ that resist further caustic damage and stimulates
mucosal prostaglandin and bicarbonate secretion
physical
barrier
Sucralfate must be taken _____ times daily
4 times daily
Prostaglandin E1 (PGE1) analogue
MISPROSTOL
Increased mucosal protection inhibit acid secretion
MISOPROSTOL
Oral administration is rapidly absorbed and metabolized to
free acid
MISOPROSTOL
Serum T1/2 : <30 minutes hence may be administered 3 – 4
times
MISOPROSTOL
Misoprostol is excreted in the
urine
T/F: Misoprostol has acid inhibitory and mucosal protective properties
T
Reduce ulcer in NSAID users
Misoprostol
Bismuth subsalicylate and Bismuth subcitrate potassium
BISMUTH COMPOUND
Coats ulcers and erosions, creating a protective layer
against acid and pepsin
BISMUTH COMPOUND
May also stimulate prostaglandin, mucus and bicarbonate
secretion
BISMUTH COMPOUND
Bismuth compound may also stimulate ______, _______, and __________ secretion
prostaglandin, mucus and bicarbonate
secretion
reduces stool frequency and liquidity in acute
infectious diarrhea, due to salicylate inhibition of
intestinal prostaglandin and chloride secretion
Bismuth subsalicylate
Bismuth subsalicylate reduces stool frequency and liquidity in acute
infectious diarrhea, due to ____________ inhibition of
intestinal _________ and _________ secretion
salicylate; prostaglandin and chloride
Bismuth subsalicylate reduces _________ and __________ in acute
infectious diarrhea, due to salicylate inhibition of
intestinal prostaglandin and chloride secretion
stool frequency and liquidity
Direct antimicrobial effec
BISMUTH COMPOUND
Causes a black tongue and black stool
BISMUTH COMPOUND
Widely used by patients for the nonspecific treatment of
dyspepsia and acute diarrhea
BISMUTH COMPOUND
Also used for the prevention of Traveller’s diarrhea
BISMUTH COMPOUND
Used in 4-drug regimen for the eradiacation of H. pylori
BISMUTH COMPOUND
4-drug regimen for the eradiacation of H. pylori:
○ PPI BID
■ Bismuth Subsalicylate (2 tab; _ mg)
■ Tetracycline( ________mg)
■ Metronidazole ( mg) times daily for
○ PPI BID
■ Bismuth Subcitrate mg
■ Metronidazole mg
■ Tetracycline mg, taken times daily for
days
○ PPI BID
■ Bismuth Subsalicylate (2 tab; 262 mg)
■ Tetracycline(250 to 500 mg)
■ Metronidazole (500 mg) four times daily for 10 to
14 days
○ PPI BID
■ Bismuth Subcitrate 140 mg
■ Metronidazole 125 mg
■ Tetracycline 125 mg, taken four times daily for 10
days
