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The Inhibition of Platelet Antiaggregating Activity of Clopidogrel by Atorvastatin Detected by Erythromycin Breath Test: a Metabolic Inhibition of Hepatic Cytochrome P450-3A

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified December 2003 by National Center for Research Resources (NCRR).
Recruitment status was:  Recruiting
Information provided by:
National Center for Research Resources (NCRR) Identifier:
First received: February 11, 2000
Last updated: June 23, 2005
Last verified: December 2003

The objective of this study is to determine if the action of the drug called clopidogrel, that you will start taking, will be decreased by another drug called atorvastatin, that you will also start taking. Clopidogrel is an oral antiplatelet agent that has been shown to prevent strokes and heart attacks. Atorvastatin is a cholesterol lowering agent.

Twenty adults 18-75 years of age requiring cholesterol-lowering agent and antiplatelet agent therapy will be recruited for this study during their cardiology clinic visitation. In one group, antiplatelet agent (clopidogrel) regimen will be administered first, then followed by cholesterol-lowering medication (atorvastatin). In the second group, atorvastatin will be administered first, followed by clopidogrel.

A new test called the erythromycin breath test will be administered to you three times during the study to measure how your liver will metabolize these drugs. Blood samples will also be obtained to assess platelet function. The criteria for exclusion are patient refusal or inability to give written consent, patients with allergic reaction to erythromycin, patients with known bleeding problems, liver disease, significant lung disease kidney disease and pregnancy. Patients with psychiatric impairment and documented history of substance abuse will also be excluded from the study.

Condition Intervention
Drug: Clopidogrel
Drug: Atorvastatin

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment

Resource links provided by NLM:

Further study details as provided by National Center for Research Resources (NCRR):


Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Males and females age 18-75 years of age without bias in racial and ethnic background, undergoing percutaneous coronary intervention requiring antiplatelet therapy: 1. Patients presented to cardiology clinic requiring cholesterol lowering agent 2. Patients presented to cardiology clinic requiring antiplatelet agent.

Exclusion Criteria:

  • Refusal or inability to give written consent
  • Allergic reaction to erythromycin
  • Have known bleeding problems, liver disease, significant lung disease kidney disease
  • Pregnancy
  • Psychiatric impairment and documented history of substance abuse
  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: NCT00004564

Contact: Wei C. Lau, M.D. 1-734-936-4280

United States, Michigan
1G323 University Hospital, Box 0048 1500 E Medical Center Drive Recruiting
Ann Arbor, Michigan, United States, 48109
Sponsors and Collaborators
National Center for Research Resources (NCRR)
  More Information Identifier: NCT00004564     History of Changes
Other Study ID Numbers: NCRR-M01RR00042-1659
M01RR000042 ( US NIH Grant/Contract Award Number )
Study First Received: February 11, 2000
Last Updated: June 23, 2005

Keywords provided by National Center for Research Resources (NCRR):
Platelet Aggregation Inhibitors
Cerebrovascular accident

Additional relevant MeSH terms:
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Lipid Metabolism Disorders
Metabolic Diseases
Atorvastatin Calcium
Platelet Aggregation Inhibitors
Anticholesteremic Agents
Hypolipidemic Agents
Molecular Mechanisms of Pharmacological Action
Lipid Regulating Agents
Hydroxymethylglutaryl-CoA Reductase Inhibitors
Enzyme Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Physiological Effects of Drugs processed this record on May 25, 2017