Effect of Amlodipine on Anti-platelet Drug Effect in Patients With Coronary Artery Disease

Ischemic Heart Disease Clinical Trial

Official title:

Effect of Amlodipine on Platelet Inhibition by Clopidogrel in Patients With Ischemic Heart Disease- a Prospective Randomized Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01203696
• Other study ID #: Aml-Clo-protocol-v1
• Status: Completed
• Phase: Phase 4
• First received: September 15, 2010
• Last updated: June 5, 2012
• Start date: July 2010
• Est. completion date: April 2011

Study information

• Verified date: June 2012
• Source: Ruttonjee Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Hong Kong: Ethics Committee
• Study type: Interventional

Clinical Trial Summary

Clopidogrel can reduce risk of cardiovascular disease by inhibiting platelet aggregation. It is metabolized to an active drug by a liver enzyme. Its efficacy may be measured by blood sampling for platelet activity, analyzed by VerifyNow device. Calcium Channel blocker (CCB) is also commonly used for blood pressure and anginal control in these patients. Dihydropyridine group of calcium channel blocker (e.g. amlodipine) inhibits this enzyme. There are observational studies reporting dihydropyridine CCB reducing clopidogrel effect, but the clinical implication is unclear.

This study test the hypothesis that there is no significant effect of dihydropyridines CCB on clopidogrel response compared with control. After giving consent, patients with suboptimal blood pressure or anginal control will be randomized to receive either dihydropyridine CCB or non-CCB as placebo. These patient will be follow-up in 1 month.

Description:

Clopidogrel is a pro-drug, which requires hepatic transformation by the cytochrome P450 isoform 3A4 to generate the active metabolite. It inhibits adenosine-5-diphosphate (ADP)-induced platelet aggregation by irreversibly blocking the platelet P2Y12 receptor. However, response to clopidogrel shows wide individual variability, and patients with high on-treatment residual ADP-induced platelet reactivity are at an increased risk of adverse cardiovascular events. Previous study suggest co-administration of CCBs is associated with decreased platelet inhibition by clopidogrel, but these observational studies are confounded by patient's characteristics baseline difference such as proportion of hypertension and diabetes.

The objective of this randomized controlled study is to compare amlodipine with placebo on anti-platelet effect of clopidogrel.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 97
• Est. completion date: April 2011
• Est. primary completion date: April 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• ischemic heart disease patient, and

• given loading or maintenance dose of clopidogrel and in need of it for 1 or more month

• and in need of additional drug for optimal BP control (aim blood pressure <130/90) or angina control.

Exclusion Criteria:

• existing use of amlodipine

• thrombocytopenia

• end stage renal failure

• allergy to clopidogrel/ amlodipine

• pregnancy/ lactation

• strong inhibitor or inducer of cytochrome P450 3A4 enzyme within 7 days before start of the study.

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacokinetics Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Coronary Artery Disease
• Heart Diseases
• Ischemic Heart Disease
• Myocardial Ischemia

Intervention

Drug:
• Amlodipine
For patient with suboptimal angina control: oral 2.5-10mg daily
• Amlodipine
For patient with suboptimal BP control: 2.5-10mg daily po

Locations

Country	Name	City	State
China	Ruttonjee Hospital	Hong Kong SAR

Sponsors (1)

Lead Sponsor	Collaborator
Ruttonjee Hospital

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Platelet reactivity unit	Platelet reactivity unit as measured by VerifyNow system	baseline and 4 th week	No
Secondary	Percentage inhibition of platelet activity	Percentage inhibition of platelet activity measured by VerifyNow system	baseline and 4th week	No