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Introduction
Peptic ulcer disease (PUD) is a common
disorder that affects millions of individuals worldwide
It is
accounting for roughly 10% of medical costs for digestive diseases
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Introduction
Major advances have been made in the
understanding PUD pathophysiology, particularly the role of Helicobacter pylori
infection & NSAIDs
This has led to important changes in diagnostic & treatment strategies, with potential for improving clinical outcome & decreasing health care costs
NSAIDs= nonsteroidal anti-inflammatory drugs
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Definitions
Ulcer:
A lesion on an epithelial surface (skin or
mucous membrane) caused by superficial loss of tissue
Erosion:
A lesion
on an epithelial surface (skin or mucous membrane) caused by superficial loss of tissue, limited to the mucosa
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Definitions
Peptic Ulcer
An ulcer of the alimentary tract mucosa,
usually in the stomach or duodenum, & rarely in
the lower esophagus, where the mucosa is exposed to the acid gastric secretion
It has to be deep enough to penetrate the muscularis mucosa
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Gastric Mucosa & Secretions
The inside of the stomach
is bathed in about 2 liters of gastric juice
every day
Gastric juice is composed of digestive enzymes & concentrated hydrochloric acid, which can readily tear apart the toughest food or microorganism
The gastroduodenal mucosal integrity is determined by protective (defensive) & damaging (aggressive) factors
Слайд 8
Gastric Mucosa & Secretions
The Defensive Forces
Bicarbonate
Mucus layer
Mucosal
blood flow
Prostaglandins
Growth factors
The Aggressive Forces
Helicobacter pylori
HCl acid
Pepsins
NSAIDs
Bile acids
Ischemia and
hypoxia.
Smoking and alcohol
When the aggressive factors increase or the defensive factors decrease, mucosal damage will result, leading to erosions & ulcerations
Слайд 9
Negative Feedback Regulation of Acid Secretion
Antral
distention Protein content
intragastric PH
Gastrin
release
somatostatin secretion
Increased gastric acid secretion
Intragastric PH
CGPR release
CGPR= calcitonin gene related peptide
Слайд 10
Pathophysiology
A peptic ulcer is a mucosal break, 3
mm or greater in size with depth, that can
involve mainly the stomach or duodenum.
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Pathophysiology
Two major variants in peptic ulcers are commonly
encountered in the clinical practice:
Duodenal Ulcer (DU)
Gastric Ulcer (GU)
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Pathophysiology
DU result from increased acid load to the
duodenum due to:
Increased acid secretion because of:
Increased parietal cell
mass
Increased gastrin secretion (e.g. Zollinger-Ellison syndrome, alcohol & spicy food)
Decreased inhibition of acid secretion, possibly by H. pylori damaging somatostatin-producing cells in the antrum
Слайд 13
Pathophysiology
DU result from increased acid load to the
duodenum due to:
Smoking impairing gastric mucosal healing
Genetic susceptibility may
play a role (more in blood gp. O)
HCO3 secretion is decreased in the duodenum by H. pylori inflammation
Слайд 14
Pathophysiology
GU results from the break down of gastric
mucosa:
Associated with gastritis affecting the body & the antrum
The
local epithelial damage occurs because of cytokines released from H. pylori & because of abnormal mucus production
Parietal cell damage occur so that acid production is normal or low
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Etiology
The two most common causes of PUD
are:
Helicobacter pylori infection ( 70-80%)
Non-steroidal anti-inflammatory drugs (NSAIDS)
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Etiology
Other uncommon causes include:
Gastrinoma (Gastrin secreting tumor)
Stress ulceration
(trauma, burns, critical illness)
Viral infections
Vascular insufficiency
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1. Etiology – Helicobacter pylori
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H.pylori Epidemiology
One half of world’s population has H.pylori
infection, with an estimated prevalence of 80-90 % in
the developing world
The annual incidence of new H. pylori infections in industrialized countries is 0.5% of the susceptible population compared with ≥ 3% in developing countries
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H.pylori as a cause of PUD
The
majority of PUD patients are
H. pylori infected
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H.pylori as a cause of PUD
95%
85%
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Pathogenesis of H. pylori infection
H. pylori is
Gram-negative, spiral & has multiple flagella at one end
Transmitted
from person-to-person by Oro–oral or feco-oral spread
No reservoir in animal or water supply
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Pathogenesis of H. pylori infection
The Flagellae make it
motile, allowing it to live deep beneath the mucus
layer
It uses an adhesin molecule to bind to epithelial cells Where the pH there is close to neutral
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Pathogenesis of H. pylori infection
Any acidity is buffered
by the organism's production of the enzyme urease, which
catalyzes the production of ammonia (NH3) from urea & raises the pH there
The bacterium stimulates chronic gastritis by provoking a local inflammatory response.
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Pathogenesis of H. pylori infection
In the cellular level:
H.
pylori express cagA & vacA genes
cagA gene ?
signals to the epithelial cells involving: - Cell replication, - Apoptosis, & - Morphology
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Pathogenesis of H. pylori infection
In the cellular level:
vacA
gene ? producing
a pore-forming protein, which has many destructing effect to the epithelium like: -↑Cell permeability & efflux of micronutrients, - Induction of apoptosis, & - Suppression of local cell immunity
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Pathogenesis of H. pylori infection
- ↓ Somatostatin production
from antral D-cells due to antral gastritis
Low somatostatin
will ↑Gastrin release from G-cell ? hypergastrinemia
This will stimulate acid production by the parietal cells ? leading to further duodenal ulceration.
Effects of H. pylori on gastric Hormones
This effect is exaggerated among smokers!
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Carcinogenic effect of H. pylori
H. pylori
Host
Factors
Other environmental
Factors
Antral gastritis
Pangastritis
DU
GU
Gastritis Cancer
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Carcinogenic effect of H. pylori
Epidemiologic evidence suggests that
infection with HP is associated with >2 fold increase
risk of gastric cancer
However due to uncertainty regarding the benefit of HP eradication on reducing cancer risk, wide-spread screening for HP in asymptomatic individuals cannot be recommended at this time
Слайд 29
For persons at high risk for gastric cancer
(e.g., first degree relatives) screening can be considered on
a case by case basis
ABLES A Z et al. American Family Physician. 2007
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2. Etiology -Non-Steroidal Anti-inflammatory Drugs (NSAIDS)
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NSAIDS
Symptomatic GI ulceration occurs in 2% - 4%
of patients treated with NSAIDs for 1 year
In view
of the million of people who take NSAIDs annually, these small percentages translate into a large number of symptomatic ulcers
The effects of aspirin & NSAIDs on the gastric mucosa ranges from mucosal hemorrhages to erosions & acute ulcers
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NSAIDS
Inhibits the production of prostaglandins precursor from membrane
fatty acids resulting in:
1. Decrease mucus & HCO3
production
2. Decrease mucosal blood flow
3. Reduce cell renewal
The drugs also generate oxygen-free radicals & products of the lipoxygenase pathway that may contribute to ulceration
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NSAIDS
Gastric acid probably aggravates NSAID-induce mucosal injury by
- Converting superficial injury to deeper mucosal necrosis,
- Interfering with haemostasis & platelet aggregation
- Impairing ulcer healing
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NSAIDS
Users of NSAIDs are at approximately 3 times
greater relative risk of serious adverse gastrointestinal events than
nonusers
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NSAIDS
Identify risk factors:
Age > 65
years (3.5-fold increased risk)
Smoking
Previous history of
GI event (e.g. ulcer bleeding 4-fold increase risk)
Concomitant drug use
Anticoagulants ( eg, warfarin; 3-fold increase)
Corticosteroid ( 2-fold increase)
Low dose aspirin alone ( 2.5-fold increase)
Aspirin + NSAIDS (4-fold increase vs aspirin alone)
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Does H. pylori Influence the Ulcer Risk in
NSAID Users?
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Does H. pylori Influence the Ulcer Risk in
NSAID Users?
Many investigators had attempted to address this question
using case-control or observational studies
To date, there are studies showing that the interaction between H. pylori and NSAIDs in ulcer development is synergistic, additive, independent or antagonistic
Слайд 39
Does H. pylori Influence the Ulcer Risk in
NSAID Users?
These conflicting results can be largely accounted for
by methodological heterogeneity and diversified host response to H. pylori infection.
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Recommendations for H.pylori Testing & Eradication in NSAID
Users
1- Patients who have a history of ulcer complication
should undergo H. pylori testing. H. pylori should be eradicated in all infected patients because it is not plausible to determine whether the ulcer complications were caused by NSAIDs or both
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Recommendations for H.pylori Testing & Eradication in NSAID
Users
3- Patients who are about to start receiving NSAIDs,
H. pylori testing & treatment reduces the ulcer risk at an affordable incremental cost
4- Since treatment with PPIs aggravate H. pylori corpus gastritis, it is advisable to test for H. pylori & eradicate if present before starting long term therapy with PPI as prophylaxis against NSAID-induced ulcers
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Clinical Presentation
Recurrent epigastric pain (the most common symptom)
Burning
Occurs
1-3 hours after meals
Relieved by food ? DU
Precipitated by
food ? GU
Relieved by antacids
Radiate to back (consider penetration)
Pain may be absent or less characteristic in one-third of patients especially in elderly patients on NSAIDs
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Clinical Presentation
Nausea, Vomiting
Dyspepsia, fatty food intolerance
Chest discomfort
Anorexia, weight
loss especially in GU
Hematemesis or melena resulting from gastrointestinal
bleeding
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Peptic Ulcer Disease
Diagnosis:
Diagnosis of ulcer
Diagnosis of H. pylori
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Diagnosis of PUD
In most patients routine laboratory
tests are usually unhelpful
Diagnosis of PUD depends mainly
on endoscopic and radiographic confirmation
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Doudenal Ulcer on Endoscopy
Doudenal Ulcer
Normal doudenal bulb
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Gastric Ulcer on Endoscopy
Chronic Gastric Ulcers
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Diagnosis of H. pylori
Non-invasive
C13 or C14 Urea Breath
Test
Stool antigen test
H. pylori IgG titer (serology)
Invasive
Gastric mucosal biopsy
Rapid
Urease test
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Diagnosis of H. pylori
Non-invasive
1. C13
or C14 Urea Breath Test
The best test for
the detection
of an active infection
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Diagnosis of H. pylori
Non-invasive
Serology for H pylori
Serum
Antibodies (IgG) to H pylori (Not for active infection)
Fecal antigen testing (Test for active HP)
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Diagnosis of H. pylori
Invasive
Upper GI endoscopy
Highly sensitive test
Patient
needs sedation
Has both diagnostic & therapeutic role
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Diagnosis of H. pylori
Invasive (endoscopy)
Diagnostic:
Detect the site and
the size of the ulcer, even small and superficial
ulcer can be detected
Detect source of bleeding
Biopsies can be taken for rapid urease test, histopathology & culture
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Diagnosis of H. pylori
Invasive (endoscopy)
Rapid urease test (
RUT)
Considered the endoscopic diagnostic test of choice
Gastric biopsy specimens
are placed in the rapid urease test kit. If H pylori are present, bacterial urease converts urea to ammonia, which changes pH and produces a COLOR change
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Diagnosis of H. pylori
Invasive (endoscopy)
* Histopathology
Done if the
rapid urease test result is negative
* Culture
Used in research studies and is not available routinely for clinical use
Слайд 56
Diagnostic Tests for Helicobacter pylori
Invasive
ABLES A
Z et al. American Family Physician. 2007
Слайд 57
Diagnostic Tests for Helicobacter pylori
Noninvasive
ABLES
A Z et al. American Family Physician. 2007
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Diagnostic Tests for Helicobacter pylori
Noninvasive
ABLES
A Z et al. American Family Physician. 2007
Слайд 59
Diagnostic Tests for Helicobacter pylori
Noninvasive
ABLES
A Z et al. American Family Physician. 2007
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Testing to Document HP Eradication
Since treatment is not
effective is some cases (> 20%), individuals at high
risk for HP-associated complications (e.g., prior bleeding ulcer) should undergo confirmatory testing with either
- Stool antigen test or
- Urea breath test to confirm HP cure
(Serology has no role in confirmatory testing)
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Testing to Document HP Eradication
Should be confirmed after
end of therapy; noninvasive testing with UBT is preferred,
4-8 weeks after completion of therapy
If ulcer recurs after eradication therapy, a more careful search for reinfection or eradication failure should be carried out by testing for presence of active infection (e.g. by histologic examination & culture, together with antibiotic-sensitivity test)
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Diagnosis of H. pylori in patients with bleeding
PU
It is limited by the decreased sensitivity of standard
invasive tests; usually, both the RUT & histologic testing should be performed & then combined with the UBT test
Infection should be considered as present when any test is positive, whereas both the invasive tests & the breath test should be negative to establish the absence of infection
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PUD – Complications
Bleeding
Perforation
Gastric outlet or duodenal obstruction
Chronic
anemia
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Complications of PUD on Endoscopy
Bleeding DU
Perforated GU
Duodenal stricture
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Treatment Goals
Rapid relief of symptoms
Healing of ulcer
Preventing
ulcer recurrences
Reducing ulcer-related complications
Reduce the morbidity (including the need
for endoscopic therapy or surgery)
Reduce the mortality
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General Strategy
Treat complications aggressively if present
Determine the
etiology of ulcer
Discontinue NSAID use if possible
Eradicate H. pylori
infection if present or strongly suspected, even if other risk factors (e.g., NSAID use) are also present;
Use antisecretory therapy to heal the ulcer if H. pylori infection is not present
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General Strategy
Smoking cessation should be encouraged
If DU
is diagnosed by endoscopy, RU testing of endoscopically obtained
gastric biopsy sample, with or without histologic examination should establish presence or absence of H. pylori
If DU is diagnosed by x-ray , then a serologic , UBT, or fecal antigen test to diagnose H. pylori infection is recommended before treating the patient for H. pylori
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Drugs Therapy
H2-Receptors antagonists
Proton pump inhibitors
Cyto-protective
agents
Prostaglandin agonists
Antacids
Antibiotics for H. pylori eradication
Слайд 71
Management of NSAIDs Ulcers
This can be considered under
two headings:
The healing of an ulcer that has
developed during NSAID or COX-2 inhibitor treatment; &
Strategies for preventing NSAID ulcers in patients who currently are ulcer free
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Healing the Established NSAIDs-Associated Ulcer
If possible, NSAID should
be stopped, as healing with a histamine H2-receptor antagonist
(H2-RA) will be faster than if the NSAID is continued
PPI have been shown in 3 randomized controlled trials to be more effective than ranitidine or misoprostol for healing NSAID ulcers when the NSAID is continued
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Best Prevention & Treatment for Upper GI Lesions
Induced by NSAIDs
There is conclusive evidence that PPIs decrease
the incidence of ulcers & erosions, & heal them when they have occurred, even when NSAIDs administration is continued
Mearin & Ponce. Drugs, 2005
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The Astronaut Study
Ranitidine 150 mg twice daily Vs.
Omeprazole 20 or 40 mg daily
Gastroduodenal ulcer healing rates
at 8weeks
Ranitidine 87% & Omeprazole 20 mg 71%
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Are Better Results Obtained if Additional Inhibition of
Gastric Acid Secretion is Achieved?
The healing rate of
H.pylori eradication, peptic ulcer healing, or the extent of mucosal damage induced by NSAIDs are clearly related to the acid inhibition level achieved with the corresponding treatment
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Reducing Risk of NSAIDs Ulcers by Choice of
Agent
Choose, where possible, an NSAID from the less damaging
end of the spectrum,
Use it in the lowest dose that is effective
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Reducing Risk of NSAIDs Ulcers by Choice of
Agent
Use highly selective COX-2 inhibitors (whether to use them
instead of a largely non-selective NSAID such as diclofenac or ibuprofen requires judgments about cost vs. benefit for the individual patient
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Reducing Risk of NSAIDs Ulcers by Choice of
Agent
In low-risk patients such as young - middle age
individuals without past history of ulcer & with no hazard-increasing cotherapies (e.g warfarin or steroids), the risk of using a non-selective NSAID is very small
Слайд 79
Preventing NSAIDs Ulcers with Co-Prescribed Gastric Protectants
Patients who
continue to require NSAIDs should receive either a PPI
or misoprostol to prevent ulcer recurrence
Слайд 80
Drugs Therapy for Treatment of PUD
1- H2-Receptors antagonists
2- H+, K+ ATPase: Proton pump inhibitors (PPIs)
3-
Cyto-protective agent (Sucalfate)
4- Prostaglandin agonists
5- Antacids
6- Antibiotics for H. pylori eradication
Слайд 81
Peptic Ulcer Disease - Treatment
Слайд 82
Degree of Acid Inhibition to Heal an Ulcer
It
has been reported that a sustained increase in pH
> 3 would be sufficient to heal an ulcer
However, one of the risk factors for refractory gastric ulcer appears to be the impossibility of maintaining gastric pH > 4 for a minimum daily period of 16 hr
Mearin & Ponce. Drugs, 2005
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The Purpose of Inhibiting Gastric Acid Secretion in
cases of Upper GI Bleeding
In upper GI bleeding, the
aim is to achieve the least acid gastric pH possible in order to prevent acid degradation of the clot & accelerate healing as much as possible
Both clinical & experimental studies suggest that extremely potent inhibition is required to achieve the intended efficacy
Mearin & Ponce. Drugs, 2005
Слайд 84
The Ideal Drug to Achieve Potent Acid inhibition
Ideal
drug should be able to maintain pH > 4
for ≥ 16 hr/day
Such level guarantee a consistent response to treatment, & sufficient for most refractory cases of peptic acid disease
Efficacy of the drug would also have to be consistent, so that such potent acid inhibition levels might be achieved in all patients, regardless of their basal acid secretion, metabolic capacity, or the presence or absence of H. pylori infection
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
These
agents are capable of 90% reduction in basal &
food-stimulated secretion of gastric acid after single dose. they are somewhat less effective in reducing nocturnal secretion
Studies have demonstrated their effectiveness in promoting the healing of DU & GU, & preventing their recurrence
These meds are equally effective in treating these conditions
Слайд 86
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Previous
recommendations were to administer these agents at least twice
a day, a single bedtime dose may be just as effective & may elicit better compliance
If administered for 6-8 weeks, can heal DU 75% & 90% respectively
Слайд 87
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Agents
Cimetidine
800mg OD or 400mg BID
Ranitidine 300mg OD or 150mg
BID
Famotidine 40mg OD or 20mg BID
Nizatidine 300mg OD or 150mg BID
Should by taken for 6-8 weeks
Слайд 88
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Pharmacokinetics
Rapidly
absorbed 1-3 hrs to peak
Ranitidine & Cimetidine hepatically metabolized
whereas Famotidine & Nizatidine are renally excreted
Dose adjustment is needed in some renal & hepatic failure patients
Слайд 89
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Side
Effects
Usually minor; include headache, dizziness, diarrhea, & muscular pain
Hallucinations
& confusion in elderly patients;
Hepatotoxicity with Ranitidine
Cimetidine elevates serum prolactin & alters estrogen metabolism in men
Gynecomastia, Galactorrhea and reduced sperm count
Слайд 90
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Drug
Interactions
Cimetidine slows microsomal metabolism of some drugs
Cimetidine causes these
in a dose-dependent but reversible manner
Inhibits the metabolism of warfarin, theophylline, diazepam & phenytoin
Ranitidine has less effect on hepatic enzymes
Слайд 91
Drugs Therapy for Treatment of PUD
1- H2-Receptors Antagonists
Drug
Interactions
Famotidine & Nizatidine has no effect on hepatic drug
metabolism
Combining H2 inhibitor with antacid has little rationale although is done. H2 antagonist + PPI inhibits efficacy of PPI
Over the counter H2 blockers now available, labeled for short-term use in heartburn & dyspepsia
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Same Acid Inhibition as Anti-H2??
No
Among anti-secretory drugs, PPIs
can inhibit gastric acid secretion with a greater efficacy than anti-H2
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Same Acid Inhibition as Anti-H2??
They are potent acid
inhibitors
Potent acid inhibition is arbitrarily defined as inhibition that achieves maintenance of an intragastric pH > 4 for ≥ 16 hr out of 24 hr
Mearin & Ponce. Drugs, 2005
Слайд 94
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Agents
Omeprazole
Lansoprazole
Pantoprazole
Rabeprazole
Esomeprazole
1st Generation
2nd Generation
Слайд 95
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Pharmacological Effect
PPIs dose-dependently inhibit basal & food acid
secretion
Decreases pepsinogen secretion &, due to the increase in intragastric pH, inhibit the proteolytic activity of pepsin
Mearin & Ponce. Drugs, 2005
Слайд 96
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Comparative Anti-secretory Efficacy of the Different PPIs
Among different
PPIs administered at standard doses, esomeprazole 40 mg/day has a greater anti-secretory potency
Rabeprazole 20 mg/day & lansoprazole 30 mg/day show a faster action, & slightly greater acid inhibition capacity than omeprazole 20 mg/day & pantoprazole 40 mg/day
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Side Effects
No evidence that they cause direct toxic
effects.
Most common adverse reactions include episodes of diarrhea, nausea, abdominal pain, dizziness, headache, or skin rash
These manifestations are most often transient & moderate in severity, not requiring reductions in compound dosage
Mearin & Ponce. Drugs, 2005
Слайд 98
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
PPIs & Vitamin B12 Deficiency
In some patients continuously
taking PPIs, a mild vitamin B12 deficiency has been seen as the result of decreased vitamin absorption
This is due to impaired release of the vitamin from food, because this is a process enhanced by the presence of an intragastric acid environment
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Time of Administration
Should by administered while fasting &
before a meal so that at the time the peak plasma concentration is reached, there is also a maximum of proton pumps activated (i.e. secreting acid)
For treatment of DU & GU should be used for 4-6 weeks
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Pharmacokinetics
How can PPIs have a Short Half-life &
a Long-lasting Effect?
Despite their short plasma half-life, PPIs exert a persistent pharmacological action because by irreversibly binding to the proton pump they render necessary the synthesis of new enzymes to re-establish gastric acid secretion
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Pharmacokinetics
Metabolism
PPIs undergo extensive first-pass metabolism in the liver,
resulting in various inactive metabolites that are excreted in the urine or bile
Metabolized by the cytochrome P450 system (mainly by isoenzymes CYP2C19 & CYP3A4)
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Pharmacokinetics
What is Esomeprazoie?
It is the S isomer of
omeprazole
Pharmacokinetic & pharmacodynamic studies suggest that this isomer undergoes less first-pass metabolism in the liver & has a lower plasma clearance as compared with omeprazole
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Dose Adjustment in Liver Failure
In patients with severe
liver failure, the area under the plasma curve for PPIs increases 7-9 fold, & their half-life is prolonged to 4-8 hr. A decrease in the usual dose of these drugs is recommended in this group of patients
Mearin & Ponce. Drugs, 2005
Слайд 104
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Drug Interactions
Theoretically, their influence on phenytoin, carbamazepine, warfarin,
& diazepam should be monitored
However, as confirmed by a recent analysis of cases recorded by (FDA), the clinical impact of these interactions is very low (rates lower than 0.1 -0.2 per 1,000,000 prescriptions), with no differences between the different PPIs
Mearin & Ponce. Drugs, 2005
Слайд 105
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Presence of H. Pylori influence Degree of Acid
inhibition ??
PPIs show a decreased efficacy in patients not infected by H. pylori. This often requires the use of higher doses of the PPI
Mearin & Ponce. Drugs, 2005
Слайд 106
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Do PPIs Have Direct Action on H.Pylori??
Yes, PPIs
inhibit the urease protecting H. pylori from acid & are effective on this microorganism in vitro, although in vivo they only achieve eradication in 10-15% of cases
Mearin & Ponce. Drugs, 2005
Слайд 107
Drugs Therapy for Treatment of PUD
2- Proton Pump
Inhibitors (PPIs)
Do PPI Promote Actions of Antibiotics in H.
Pylori Eradication?
In vitro, PPIs have additive even synergistic effect with several antimicrobial agents
Studies suggest that high dose omeprazole increase amoxycillin level in gastric juice, & high dose of PPIs improve H.pylori cure rate when given with amoxycillin
Clarithromycin activity against H. pylori is enhanced as gastric pH increases
Mearin & Ponce. Drugs, 2005
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Drugs Therapy for Treatment of PUD
3- Cyto-Protective Agent
( Sucalfate)
Sucralfate = complex of Aluminum Hydroxide & Sulfated
Sucrose
Binds to positively charged groups in proteins, glycoproteins of necrotic tissue (coat ulcerated mucosa)
Not absorbed systemically
Require acidic media to dissolve & coates the ulcerative tissue so, it can not be given with H2-antagonist, PPIs, & antacids
Слайд 109
Drugs Therapy for Treatment of PUD
3- Cyto-Protective Agent
( Sucalfate)
Administration
Should not be given with food, give 1hr
before or 3hr after meal
Dose: 1gm/ 4times daily or 2 gm/ 2times daily
Must be given for 6-8 weeks
Large tablet & difficult to swallow
Слайд 110
Drugs Therapy for Treatment of PUD
3- Cyto-Protective Agent
( Sucalfate)
Side Effects
Constipation; black stool & dry mouth
It is
very safe in pregnancy
Слайд 111
Drugs Therapy for Treatment of PUD
4- Prostaglandin Agonists
(PGE1) Misoprostol
Inhibits secretion of HCl & stimulates secretion of
mucus & bicarbonatemis
It is a methyl analog of PGE1
It is approved for prevention of ulcer induced by NSAIDs
Слайд 112
Drugs Therapy for Treatment of PUD
4- Prostaglandin Agonists
(PGE1) Misoprostol
Optimal role in ulcer treatment is difficult to
define
PPIs may be as effective as misoprostol for this indication
Routine clinical prophylaxis of NSAIDs-induced ulcers may not be justified
However, in patients with rheumatoid arthritis requiring NSAIDs therapy, prophylaxis with Misoprostol or a PPI may be cost-effective
Слайд 113
Drugs Therapy for Treatment of PUD
4- Prostaglandin Agonists
(PGE1) Misoprostol
Administration
Should be given 4 time/ day ( inconvenient)
Side effects
Up to 20% develop diarrhea & cramps
Category X
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Drugs Therapy for Treatment of PUD
5- Antacids
Weak bases
that react with gastric acid to form water &
salt (Neutralize acid)
Studies indicate mucosal protection either through stimulation of prostaglandin production or binding of unidentified injurious substance
Antacids vary in palatability & price
Слайд 115
Drugs Therapy for Treatment of PUD
5- Antacids
Antacids contain
either Sodium-bicarbonate, Aluminum-hydroxide, magnesium-hydroxide & calcium carbonate
Require large neutralizing
capacity (a single dose of 156 meq antacid given 1 hr after meal effectively neutralize gastric acid for 2 hr, a second dose given 3 hr after eating maintains the effect for over 4 hr after the meal)
Слайд 116
Drugs Therapy for Treatment of PUD
5- Antacids
Very inconvenient
to administer
Tablet antacids are generally weak in their neutralizing
capability, & a large number of tablets would be required for this high-dose regimen
Слайд 117
Drugs Therapy for Treatment of PUD
5- Antacids
Side Effects
Cation
absorption (sodium, magnesium, aluminum, calcium) leads to systemic alkalosis
(concern with renal impairment)
Sodium content an issue with congestive heart failure
Слайд 118
Drugs Therapy for Treatment of PUD
5- Antacids
Side Effects
Aluminum
hydroxide may be constipating, Magnesium hydroxide may produce diarrhea
so, they used in combination
Calcium-carbonate containing antacids work rapidly & very effective but large dose may cause calciuria
Слайд 119
The Mechanism & Side Effects of Various Acid
Suppressive Medications
Слайд 120
Drugs Therapy for Treatment of PUD
6- Antibiotics for
H. Pylori Eradication
H. pylori eradication significantly reduce the
risk of ulcer recurrence & re-bleeding & less expensive than chronic antisecretory therapy
Continuing antisecretory therapy for > 2 weeks following antibiotic treatment is unnecessary after H.pylori eradication
ABLES A Z et al. American Family Physician. 2007
Слайд 121
To Select Therapy for H. pylori Eradication
Duration
of treatment & adverse effects
should be considered
Слайд 122
Duration of H. Pylori Eradication Therapy
Until recently,
the recommended duration of therapy for H.pylori eradication was
10 -14 days
There are number of recent studies evaluated one-, five-, & seven-day regimens
Although not proven, potential benefits of shorter regimens include better compliance, fewer adverse drug effects, & reduced cost to the patient
ABLES A Z et al. American Family Physician. 2007
Слайд 123
Adverse Effects
The most commonly reported adverse events
were nausea, vomiting, & diarrhea
A bitter or metallic
taste in the mouth is associated with eradication regimens containing clarithromycin
Bismuth subsalicylate may cause a temporary grayish-black discoloration of the stool
ABLES A Z et al. American Family Physician. 2007
Слайд 124
Selected Long-Duration Regimens for H. pylori Eradication
ABLES
A Z et al. American Family Physician. 2007
Слайд 125
Short-Course Therapy for Eradication of Helicobacter pylori
ABLES
A Z et al. American Family Physician. 2007
Слайд 126
Short-Course Therapy for Eradication of Helicobacter pylori
ABLES
A Z et al. American Family Physician. 2007
Слайд 127
Short-Course Therapy for Eradication of Helicobacter pylori
ABLES
A Z et al. American Family Physician. 2007
Слайд 128
Resistance
Resistant H. pylori has been documented in
cases of failed eradication therapy based on biopsy &
culture results & is of great concern in patients at high risk for complications of H.pylori infection
ABLES A Z et al. American Family Physician. 2007
Слайд 129
Resistance
Resistance rate to clarithromycin is currently 2-30%
& to metronidazole 15-66%
Primary resistance to clarithromycin is a
strong predictive risk factor for treatment failure, whereas primary resistance to metronidazole does not always lead to treatment failure
ABLES A Z et al. American Family Physician. 2007
Слайд 130
Resistance
70 % of patients failing one or
more regimens responded well to triple-drug therapy that included:
Pantoprazole, amoxicillin, & levofloxacin for 10 days
ABLES A Z et al. American Family Physician. 2007
Слайд 131
Resistance
A meta-analysis of current literature on treatment
of resistant H. pylori showed benefit in using quadruple
drug therapy, including:
Clarithromycin + ranitidine + bismuth + amoxicillin (1 g twice daily) therapy, as well as a combination of
PPIs (standard dosage for 10 days) + bismuth + metronidazole + tetracycline
ABLES A Z et al. American Family Physician. 2007
Слайд 132
Recurrence
Recurrence of H. pylori infection is defined
by:
A positive result on urea breath
or stool antigen testing six or more months after documented successful
ABLES A Z et al. American Family Physician. 2007
Слайд 133
Recurrence
Risk factors for recurrence include:
Non-ulcer dyspepsia
Persistence of
chronic gastritis after eradication therapy
Female gender
Intellectual disability
Younger age
High rates
of primary infection
Higher urea breath test values
ABLES A Z et al. American Family Physician. 2007
Слайд 134
Recurrence
Recurrence rates worldwide vary but lower in
developed countries
In the primary care setting, physicians may choose
to treat recurrences with an alternative eradication regimen, depending on symptoms & risk factors for complications of infection
It is too early to know whether shorter courses of eradication therapy will be associated with a higher resistance rate
ABLES A Z et al. American Family Physician. 2007