Patients with Zollinger-Ellison Syndrome suffer from ulcers of the upper gastrointestinal
tract, higher than normal levels of gastric acid, and tumors of the pancreas known as
non-beta islet cell tumors. Patients with Zollinger-Ellison Syndrome require continuous
control of their gastric acid secretion. If gastric acid levels are permitted to rise higher
than normal, patients may develop severe ulcers and other complications.
This study will attempt to determine the effectiveness of Omeprazole (Prilosec) in the
treatment of patients with Zollinger-Ellison Syndrome. Omeprazole is a drug that functions
to decrease the amount of gastric acid secreted.
Patients for this study will be selected based on a previous diagnosis of Zollinger-Ellison
Syndrome and/or idiopathic (unknown cause) high levels of gastric acid secretion. The
patients will undergo an evaluation including history and physical examination as well as
necessary laboratory tests. The proper dose of Omeprazole will then be determined in each
patient . The proper dose of Omeprazole is considered the minimum amount of omeprazole
required to lower gastric acid to a safe level.
Every year patients participating in this study will undergo a physical examination and
history. They will be questioned about symptoms associated with Zollinger-Ellison Syndrome.
Gastric acid levels will be taken and evaluated and patients will undergo an upper
The effectiveness of the treatment will be measured by a clinical history to determine the
control of symptoms due to high levels of gastric acid secretion.
Patients with Zollinger-Ellison syndrome require continuous control of their gastric acid
secretion or else severe complications of peptic ulcer disease will occur. This study
investigates the long-term efficacy of the oral gastric acid antisecretory drug, Omeprazole,
which functions as a H+ - K+ ATPase inhibitor. Long-term safety will also be investigated.
Also investigated is the ability of the parenteral H+-K+ ATPase inhibitor, pantoprazole to
control acid secretion short-term, when oral Omeprazole cannot be used.
In this study the proper maintenance dose of oral Omeprazole will be determined in each
patient by determining the minimal dose of drug that reduces acid secretion to safe levels.
Patients will be examined at least annually for evidence of continued efficacy and safety.
Efficacy will be assessed by clinical history to assess control of symptoms due to gastric
acid hypersecretion, measurements of gastric acid secretion while on Omeprazole to determine
continued effectiveness of the drug and upper gastrointestinal endoscopy to assess changes
in the gastrointestinal mucosa. Safety will be determined by assessing clinical and
laboratory parameters such as changes in hematologic or clinical chemistry parameters.
Possible drug induced changes in the gastric mucosa will be assessed by gastric biopsies.
With intravenous pantoprazole the ability of the recommended dose of 80 mg three times a day
to control acid secretion will be investigated and if this fails, 80 mg four times a day
will be assessed.
- INCLUSION CRITERIA:
Subjects for receiving oral Omeprazole will be patients who have idiopathic gastric acid
hypersecretion with basal rates of gastric acid secretion of greater than 15 mEq/hr and
patients with Zollinger-Ellison syndrome with basal acid output greater than 10mEq/hr are
Subjects with gastric acid hypersecretory states who are being treated with various
antisecretory drugs under the protocols entitled "Medical Therapy of Zollinger-Ellison
Syndrome" (89-DK-0015) are eligible.
Patients must be 18 years of age or older.
Female patients of childbearing age who are attempting to become pregnant, are pregnant,
or are unwilling to practice effective birth control will be excluded.
Patients who develop adverse reactions or allergic responses to Omeprazole will be