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Clopidogrel Proton-Pump Inhibitors Study

This study has been withdrawn prior to enrollment.
(Since the published data resolved the study goals we decided not to start it)
Information provided by (Responsible Party):
Sheba Medical Center Identifier:
First received: November 18, 2009
Last updated: October 19, 2016
Last verified: October 2016
To find out the impact of two different proton-pump inhibitors (PPIs) (Omeprazole and Pantoprazole) on platelet function in patients with stable coronary artery disease (CAD) on clopidogrel therapy.

Condition Intervention Phase
Coronary Artery Disease Drug: Omeprazole Drug: Pantoprazole Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Clopidogrel Proton-Pump Inhibitors Study

Resource links provided by NLM:

Further study details as provided by Sheba Medical Center:

Primary Outcome Measures:
  • Platelet function tests. [ Time Frame: 30 days ]

Enrollment: 0
Study Start Date: December 2012
Study Completion Date: December 2012
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Omeprazole
Patients will be taking omeprazole tablets 40 mg QD for 30 days
Drug: Omeprazole
All patients will be taking omeprazole (Losec, Abic Inc., Israel) tablets 40 mg QD for 30 days
Other Name: Losec
Active Comparator: Pantoprazole
Patients will be taking Pantoprazole tablets 40 mg QD for 30 days
Drug: Pantoprazole
Pantoprazole tablets (Controloc 40, 40 mg/day, Nycomed, Perrigo Inc., Israel). All patients will take pantoprazole tablets 40 mg QD for 30 days
Other Name: Controloc

Detailed Description:

On June 19, 2009 The European Medicines Agency (EMEA) has issued a public statement on a possible interaction between clopidogrel (Plavix, Sanofi-Aventis/Bristol-Myers Squibb)and proton-pump inhibitors (PPIs) and has recommended that the product information for all clopidogrel-containing medicines be amended to discourage concomitant use of PPIs unless absolutely necessary. The UK medicines regulator, the Medicines and Healthcare Products Regulatory Agency (MHRA), has also issued advice to GPs that concomitant use of a PPI with clopidogrel is not recommended unless considered essential, urging a review of the prescribing of PPIs at the next appointment for patients taking clopidogrel. This follows an "early communication" issued by the US FDA earlier this year, stating that PPIs might interfere with the effectiveness of clopidogrel and that clinicians should reevaluate starting or continuing treatment with a PPI in patients taking clopidogrel.

There is a concern that the studies on which these warnings are based have many limitations and that it is far from certain whether there really is an interaction between clopidogrel and PPIs.

Another point of uncertainty is whether there may be a difference between individual PPIs, with some pharmacodynamic studies suggesting an interaction with omeprazole but not with pantoprazole. The clinical evidence, however, is conflicting. There has been one clinical trial from Canada suggesting an interaction with omeprazole but not with pantoprazole. From a mechanistic view it is known that omeprazole is metabolized by the CYP219 enzyme, which converts clopidogrel into its active metabolite. And while pantoprazole can also be metabolized by this enzyme, it also uses other routes.

Thus, the primary goal of the current study is to find out the impact of two different PPIs (Omeprazole, Losec, and Pantoprazole) on platelet function in patients with stable coronary artery disease (CAD) on clopidogrel therapy.

Forty patients with stable CAD will be randomized to receive either omeprazole tables (Losec, 40 mg/day, Abic Inc., Israel) or pantoprazole tables (Controloc 40, 40 mg/day, Nycomed, Perrigo Inc., Israel) for 1 month (Phase 1), followed by a 4-week washout period, and the alternative treatment for 1 month (Phase 2).Platelet function tests will be assessed 4 times: before and after each study phase. Following an overnight fast, ECG and blood tests for measurements of platelet function, lipids, blood cell count, electrolytes, fasting glucose, and high-sensitivity C-reactive protein (hs-CRP), will be performed. The blood samples, except those for platelet function, will be centrifuged immediately for 15 minutes at 3000/min. The sera will be stored at -20° C, and will be tested at the end of the study. Blood samples for platelet function will be assessed immediately after the blood is drawn. All blood samples will be evaluated in the same laboratory and by the same operator who will be blinded to the patients' clinical status and PPIs allocation.

All patients will be instructed to continue taking their regular medications throughout the study period. In addition, patients will be instructed not to add any medications (including over the counter medications) and to record any change in concomitant medications throughout the study period.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion criteria:

  1. Male or female ≥ 18 years; signed informed consent
  2. Outpatient CAD patients on aspirin tablets 100-325 mg daily and clopidogrel tablets 75 mg daily.
  3. Left ventricular (LV) systolic dysfunction ≥ 40% measured within the past 6 months.
  4. No changes in cardiac medications during 2 weeks prior to enrollment.

Exclusion criteria:

  1. Presence of transplanted tissue or organ or LVAD
  2. AICD or CRT or CRTD patients.
  3. Acute MI, CABG, PCI within past 3 months.
  4. Congestive heart failure (CHF) ≥ NYHA 2.
  5. Ejection fraction < 40% measured within the past 6 months.
  6. Malignancy.
  7. Active myocarditis, or cardiomyopathy.
  8. HIV infection or immunodeficiency state.
  9. Chronic viral infection.
  10. Acute systemic infection requiring antibiotics.
  11. Chronic diarrhea or malabsorption.
  12. Statin therapy initiation ≤ 3 months.
  13. Diabetes mellitus type 1.
  14. Diabetes mellitus type 2 with HbA1C > 7%
  15. Low-density lipoprotein cholesterol (LDL-C) > 100 mg/dL.
  16. Not on statin therapy.
  17. Liver function tests (LFT) ≥ x 3 upper limit of normal (ULN) or creatinine kinase (CPK) ≥ x 10 ULN.
  18. Hypo/hyper thyroidism.
  19. Liver dysfunction.
  20. Renal failure with serum creatinine ≥ 2 mg/dL.
  21. Alcohol or drug abuse.
  22. Refuse to sign informed consent.
  23. On the following therapy: Amiodarone, coumadin, any antibiotics.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01016717

Leviev Heart Center, Sheba Medical Center
Tel Hashomer, Israel, 52621
Sponsors and Collaborators
Sheba Medical Center
Principal Investigator: Michael Shechter, MD, MA Leviev Heart Center, Sheba Medical Center, Tel Hashomer
  More Information

Additional Information:
Responsible Party: Sheba Medical Center Identifier: NCT01016717     History of Changes
Other Study ID Numbers: SHEBA-09-7345-MS-CTIL
Study First Received: November 18, 2009
Last Updated: October 19, 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by Sheba Medical Center:
platelet function
coronary disease

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Arterial Occlusive Diseases
Vascular Diseases
Proton Pump Inhibitors
Platelet Aggregation Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Anti-Ulcer Agents
Gastrointestinal Agents
Enzyme Inhibitors processed this record on August 18, 2017