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Pharmacological Study That Measures Omeprazole Effect on Aspirins Absorption in Healthy Volunteers

This study has been completed.
Information provided by:
Assaf-Harofeh Medical Center Identifier:
First received: May 3, 2009
Last updated: January 2, 2010
Last verified: November 2009

Aspirin is a weak acid that crosses the gastric and intestinal mucosa by passive diffusion while in its lipophilic nature.Omeprazole, a proton pump inhibitor, inhibits gastric acid secretion.

We assumed that omeprazole inhibits aspirin absorption, thus reducing its action on platelets.

healthy volunteers, with no known peptic disease or bleeding disorders will be enrolled.

All volunteers will receive 7 days of Aspirin (100mg) alone, followed by 14 days of Aspirin and Omeprazole 20mg twice daily for 3 days and then 20mg once daily.

Blood levels of Aspirin will be determined by High performance liquid chromatography (HPLC), 0, 1, 2, 4, 6, 10, 24 hours after the administration of Aspirin alone on day 7 and Aspirin plus Omeprazole on day 21.

Platelet function tests will be determined by platelet-rich plasma aggregometry in response to Arachidonic acid (500mg/ml), Ristocetin (1.5mg/ml) and Adenosine 5'-diphosphate (20mM) on day 0 as baseline and on day 7 and 21 of the study.

Condition Intervention
Aspirin Blood Level Proton Pump Inhiditor Treatment Drug: aspirin and omeprazole

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Official Title: The Effect of Proton Pump Inhibitor (Omeprazole) on Acetosalisylic Acid Absorption.

Resource links provided by NLM:

Further study details as provided by Assaf-Harofeh Medical Center:

Primary Outcome Measures:
  • Aspirin Level in Blood (Area Under the Curve) [ Time Frame: on day 7,on day 21 ]

Secondary Outcome Measures:
  • Platelet Function Tests [ Time Frame: on day 0 as a baseline and on day 7 and 21 of the study. ]

Enrollment: 9
Study Start Date: March 2007
Study Completion Date: June 2007
Primary Completion Date: June 2007 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: aspirin and omeprazole
    aspirin 100 mg, once daily aspirin 100 mg and omeprazole 20 mg both once daily.

Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

-healthy volunteers

Exclusion Criteria:

  • pretreatment with aspirin
  • pretreatment with non steroidal anti inflamatory drugs
  • pretreatment with antacids
  • history of peptic ulcer disease
  • coagulation or aggregation disorder.
  Contacts and Locations
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Please refer to this study by its identifier: NCT01061034

Assaf Harofeh Medical Center
Zerifin, Israel
Sponsors and Collaborators
Assaf-Harofeh Medical Center
Study Director: ahuva golik, prop. asaf-harofemedical center
  More Information

Responsible Party: dr. keren doenyas barak, internal medicine A asaf-harofeh medical center Identifier: NCT01061034     History of Changes
Other Study ID Numbers: 180/07
Study First Received: May 3, 2009
Results First Received: May 3, 2009
Last Updated: January 2, 2010

Keywords provided by Assaf-Harofeh Medical Center:
proton pump inhiditor

Additional relevant MeSH terms:
Anti-Inflammatory Agents, Non-Steroidal
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Inflammatory Agents
Antirheumatic Agents
Fibrinolytic Agents
Fibrin Modulating Agents
Molecular Mechanisms of Pharmacological Action
Platelet Aggregation Inhibitors
Cyclooxygenase Inhibitors
Enzyme Inhibitors
Anti-Ulcer Agents
Gastrointestinal Agents
Proton Pump Inhibitors processed this record on August 22, 2017