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Improving
Treatment of Acid-Related Disorders
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Certified for 0.25
Category 1 AMA Credit
Sponsored by the University
of Alabama School of Medicine
Division of Continuing Medical Education
| Release Date:
April 20, 2006 |
Expiration
Date: April 20, 2009
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| TARGET
AUDIENCE: |
| Primary
care physicians |
| ABSTRACT: |
| The discovery
of the etiology of acid-related disorders and their treatment
is one of the 20th century's most amazing scientific achievements.
Most of this knowledge would not have been forthcoming without
development of flexible fiber-optic endoscopy. |
| OBJECTIVES: |
| The reader
will understand the causes and treatments for bacterial and
nonbacterial ulcer disease and gastroesophageal reflux disease. |
| Top of Page |
| FACULTY: |
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Basil
I. Hirschowitz, MD
Professor Emeritus
Department of Medicine, Division of Gastroenterology
The University of Alabama at Birmingham
Birmingham, Alabama
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| DISCLOSURE: |
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In accordance with the Accreditation
Council for Continuing Medical Education Standards for
Commercial Support, Dr. Hirschowitz discloses grants and
research support from TAP Pharmaceuticals and he is a consultant
for TAP Pharmaceuticals.
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| CME
PARTICIPATION: |
| To participate
in this program for CME credit, please review the objectives
before beginning the program. Complete the course and the
self-assessment test before April 20, 2009 to receive CME
credit. Your certificate will then be available online. This
process should take approximately 15 minutes. |
| ACCREDITATION: |
|
The University of Alabama School
of Medicine is accredited by the Accreditation Council
for Continuing Medical Education (ACCME) to provide continuing
medical education for physicians.
The University of Alabama School
of Medicine designates this educational activity for a
maximum of 0.25 Category 1 credit toward the AMA Physician's
Recognition Award. Physicians should only claim credit
commensurate with the extent of their participation in
the activity.
The boards of nursing in many
states, including Alabama, recognize Category 1 continuing
medical education courses as acceptable activities for
the renewal of license to practice nursing.
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| Top of Page |
| Introduction: |
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Proton-pump
inhibitors (PPI), the best selling drugs in the world today,
are largely used for treatment of symptoms and disease
due to gastroesophageal reflux and peptic ulcers and as
prophylaxis in persons taking ulcerogenic medications.
The National Institute of Diabetes and Digestive and Kidney
Diseases estimates more than 14 million Americans live
with peptic ulcer disease, which for decades was attributed
to stress and lifestyle issues.
Australian
researchers Barry J. Marshall, MD, and J. Robin Warren,
MD, challenged prevailing dogma related to cause of peptic
ulcer disease and found the spiral-shaped bacterium Helicobacter
pylori causes the majority of peptic ulcers (duodenal or
gastric). The pair received the 2005 Nobel Prize in Physiology
or Medicine for their discovery of H pylori and its role
in gastritis and peptic ulcer disease.
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“Ulcers
caused by H pylori can be treated with new 7- to 10-day
combinations of PPIs and antibiotics, which eradicate most
H pylori, thereby permanently curing ulcers caused by the
bacteria. What remains are a proportion of peptic ulcers
not related to H pylori, esophageal reflux, and hypersecretion
issues that must be treated with appropriate medical therapies,” explains
UAB gastroenterologist Basil I. Hirschowitz, MD.
Hirschowitz
is recognized internationally for his invention of an improved
optical glass fiber and the development of the flexible
endoscope, which modernized gastroenterologic diagnostic
and treatment techniques and which he continues to refine
today.
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Peptic
Ulcers of Nonbacterial Origin
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Between
20% and 30% of peptic ulcers are not caused by H pylori,
Hirschowitz says. Common symptoms are dyspepsia, including
epigastric pain, nausea, and vomiting.
Independent
of H pylori, nonsteroidal anti-inflammatory drugs (NSAIDs),
including aspirin, are the second most common cause of
peptic ulcers, although patients may misrepresent or not
fully understand their NSAID intake. A 2002 UAB study found
nearly 7% of 1845 peptic ulcers were due to NSAIDs or aspirin
and resistant to treatment. Aspirin abuse was identified
by evidence from elevated serum salicylate levels, even
though many patients denied aspirin use (Jour Clin
Gastro. 2002;34:523-528).
“Many
did not understand they were taking aspirin, which is found
in numerous common over-the-counter medications, such as
Stanback headache powders and Alka Seltzer,” Hirschowitz
says.
“Aspirin-abuse
ulcers differ from the usual H pylori peptic ulcers and
from those due to acid hypersecretion or a gastrin-producing
pancreatic tumor called a gastrinoma,” explains Hirschowitz,
the study’s lead author. “Aspirin-abuse ulcers
present atypically, often in multiple locations, and with
many complications. Bleeding, pyloric or duodenal stenosis,
esophageal strictures, and perforations are more common
in peptic ulcers related to aspirin than in peptic ulcers
due to other causes. Unless aspirin abuse is stopped, these
ulcers remain incurable and extremely dangerous.”
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| Top of Page |
| Gastroesophageal
Reflux |
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Abnormal reflux of gastric contents into the esophagus causes
heartburn, the telltale symptom of gastroesophageal reflux.
Reflux affects more than 60 million Americans at least once
a month and is an everyday problem for about 25 million.
Reflux of gastric contents can result in mucosal damage (esophagitis)
with esophageal erosion or ulceration and further complications,
such as stricture or Barrett esophagus, collectively defined
as gastroesophageal reflux disease (GERD).
Gastroesophageal reflux is usually due to lower esophageal
sphincter incompetence, abnormal transient lower esophageal
sphincter relaxation, or hiatal hernia. Gradually, acid,
pepsin, trypsin, or bile acids overcome esophageal acid clearance
and mucosal resistance, leading to esophagitis.
“Endoscopy demonstrating esophagitis or Barrett esophagus
[a possible predictor of esophageal adenocarcinoma] confirms
gastroesophageal reflux, yet many symptomatic patients present
with normal endoscopy, so-called nonerosive reflux disease.
Whether esophagitis is present or not, patients with gastroesophageal
reflux symptoms have pathologic amounts of acid reflux that
are best controlled with a PPI,” he advises.
In its most recent gastroesophageal reflux guidelines, the
American College of Gastroenterology advised offering empirical
treatment for patients with reflux-consistent symptoms, ie,
heartburn, and to reasonably assume the diagnosis of reflux
in patients responsive to appropriate therapy. However, in
reflux patients, physicians should further evaluate alarm
symptoms, such as chronic undiagnosed cough, hoarseness,
or both, difficulty swallowing, bleeding, anemia, or weight
loss by endoscopy or barium swallow (Available at: www.acg.gi.org/physicians/guidelines/GERDTreatment.pdf.
Accessed March 14, 2006).
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| Top of Page |
| Acid
Hypersecretion |
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A further
subset of ulcers not due to H pylori or NSAIDs, comprising
about 10% of duodenal ulcers, are
caused by excessive
acid production due to an overactive vagus nerve. “Resembling
Zollinger-Ellison syndrome, these ulcers are not caused by
a gastrinoma,” Hirschowitz says.
Excessive acid secretion in Zollinger- Ellison syndrome,
an uncommon condition, is caused by gastrin-secreting tumors,
which are often multiple, usually located in or near the
pancreas, and sometimes metastasize to regional lymph nodes
and occasionally beyond, Hirschowitz says. Acid hypersecretion
from elevated gastrin causes continuous high rates of acid
secretion, leading to severe ulcer disease, esophagitis,
diarrhea, and frequent complications such as bleeding or
perforation.
“Because gastrinomas are uncommon, they are often
misdiagnosed. Additionally, they can present with conventional
symptoms of peptic ulcers,” he notes. However, patients
with underlying gastrinomas may have multiple and rapidly
recurrent ulcers. These ulcers are not related to H pylori or NSAIDs. Persistent peptic ulcers with esophagitis and
unexplained diarrhea or hypercalcemia, excessive vomiting,
or weight loss may be clues to the diagnosis of Zollinger-Ellison
syndrome.
“If the diagnosis is suspected, elevated serum gastrin
and very high gastric acid secretion indicate Zollinger-Ellison.
Zollinger-Ellison ulcers usually respond to treatment, but
relapse rapidly. PPIs are the preferred and essential treatment,
suppressing acid to normal or low levels and thereby controlling
the disease indefinitely. Patients must be carefully and
consistently monitored for recurrent disease,” he says. “In
the long term, surgery to remove a gastrinoma is successful
in no more than 10% to 20% of cases and should be offered
to patients rarely, and then only after intensive and specialized
tests.”
Gastrinomas occur with equal frequency among men and women,
yet duodenal ulcers with hyperacid secretion not due to gastrinomas
occur almost exclusively in men, UAB studies report. An ongoing,
17-year prospective study examined more than 80 acid hypersecreting
patients (including 60 with Zollinger-Ellison syndrome) taking
individually optimized doses of lansoprazole. Hirschowitz
and colleagues found an overwhelming majority of patients
with optimal medical suppression of acid had good or excellent
long-term outcomes without surgery, with relapse rates lower
than 5% (Clin Gastroenterol Hepatol. 2005;3:39-48).
Before
treatment, 94% of participants had duodenal ulcers, 64%
had esophagitis, 60% had one or more
bleeding episodes,
13% had perforated ulcers, 90% had pain, 60% had heartburn,
and about 40% had diarrhea, vomiting, weight loss, or all
three. “Overall, treatment reduced symptoms and disease
manifestations, including bleeding and perforation, by 90%
or more,” he says. “Interestingly, in patients
with Zollinger-Ellison syndrome, the stomach is immune to
excess acid production. Gastric ulcers are more common in
people affected by H pylori or NSAID use but extremely rare
with Zollinger-Ellison.”
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| Top of Page |
| Diagnostic
Tools |
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In acid
hypersecretion and severe esophagitis, serum gastrin levels
and gastric analysis measuring the
output of stomach
acid provide important information about diagnosis and management. “Gastric
analysis provides specific benchmarks [15 mEq/h] for diagnosing
Zollinger-Ellison and less than 5 mEq/hr for optimizing PPI
dosage,” Hirschowitz says. “Since high gastrin
levels occur with both gastrinomas and nonacid producing
pernicious anemia, empiric analysis [high vs 0] of acid output
is critical to proper diagnosis.”
Endoscopy
is essential for diagnosis of upper gastrointestinal diseases
including esophagitis, pain,
and bleeding. In some
cases, treatment, especially for heartburn and GERD, can
precede diagnosis, he says. “Some patients, especially
those with infrequent heartburn, should be treated first,
with endoscopy reserved for those whose symptoms are not
controlled with medications or who have alarm symptoms such
as dysphagia, odynophagia, or weight loss. Esophagogastroduodenoscopy
can be used for biopsy of Barrett esophagus every 1 to 3
years, depending on whether atypia is present on biopsy.”
Persistent
symptoms of peptic ulcer disease require an endoscopy for
accurate diagnosis of location,
size, signs of bleeding,
pH measurements of gastric contents, and H pylori, which
is also diagnosable by nonendoscopic means, he says. “Serial
endoscopy for ulcers, which are adequately cured in nearly
all patients, is not indicated, except perhaps for those
with persistent symptoms that may have a different cause,
such as NSAIDs, bleeding, or Barrett esophagus.”
Interventional endoscopy is used for control of bleeding,
removal of polyps, superficial cancers, and esophageal or
pyloric strictures. |
| Top of Page |
| Drug
Therapy |
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With
Hirschowitz at the helm of ulcer studies, UAB has been
at the forefront of decades of research on
drugs to suppress
acid secretion. “Prior to the 1974 development of histamine
H2-receptor antagonists, for which British pharmacologist
James Black earned the Nobel Prize, the only available drugs
for treating acid disorders were belladonna [atropine] and
antacids, and clinicians relied heavily on surgery. Modern
H2 antagonists dramatically changed treatment. UAB has conducted
extensive research and testing on antagonists such as cimetidine
[Tagamet] and ranitidine [Zantac] to control acid disorders,” he
says.
In the
early 1980s, PPIs were developed as potent acid inhibitors. “Specifically,
they intervene in the final proton-pump or acid-pump pathway
[H+-K+-ATPase], shutting off acid output and functioning
as ideal medicines for treating acid-related ulceration and
esophageal reflux,” he says.
The more
potent PPIs have largely replaced H2-receptor antagonists
for long-term control of acid-related
diseases. PPIs have
a well-established safety profile, although some questions
remain about potential side effects over long periods. “Rat
studies indicating long-term acid suppression could lead
to gastric carcinoid development prompted a temporary delay
in Food and Drug Administration approval of PPIs in the 1980s.
However, more than 300 million people have taken these drugs,
and human cancer risks have failed to materialize,” Hirschowitz
says.
“Yet, lifelong treatment with PPI drugs is not for
everyone, he says. “Not all patients are equally responsive
to the medicines, but optimizing treatment regimens based
on gastric analysis significantly improves outcomes. In the
20th century, eradicating H pylori and targeting individualized
treatments revolutionized management of acid disorders,” he
concludes.
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| Top of Page |
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For
more information:
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Dr.
Basil Hirschowitz
1-800-UAB-MIST
mist@uabmc.edu
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| Self-Assessment
Test: |
| To
apply for 0.25 Category 1 credit, complete the self-assessment
test and you should receive an online certificate immediately. |
|
To
take the test click
here!
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