Assessment of platelet inhibitory response to clopidogrel when coadministered with a proton pump inhibitor - Plavix and PPI study

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2009-011543-40-GB

Enrollment

Registered

2010-10-19

Start date

2009-07-09

Completion date

Unknown

Last updated

2020-10-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

To investigate in patients undergoing elective coronary stenting, the interaction between omeprazole, rabeprazole and ranitidine on clopodogrel inhibition of platelet activity in wild type (wt/wt) CYP2C19 “extensive metabolisers”, using VerifyNow-P2Y12 assay clopidogrel assay. We will also indirectly assess the effect of clopidogrel on acid suppression by measuring gastrin hormone levels that are directly related to stomach pH.

Interventions

Trade Name: Omeprazole (Losec) Product Name: Omeprazole Pharmaceutical Form: Tablet Trade Name: Pariet Product Name: Pariet (Rabeprazole) Pharmaceutical Form: Tablet Trade Name: Zantac (Ranitidine)

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Age >18 Able to consent Elective PCI Bleeding risk (eScore>15) and indication for PPI when on DAP Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range

Exclusion criteria

Exclusion criteria: Allergic to omeprazole, rabeprazole or ranitidine Already on a PPI Pregnant

Design outcomes

Primary

Measure	Time frame
Main Objective: To study platelet activity using the bed-side VerifyNow assay to determine whether different gastroprotective agents (prescribed with dual anti-platelet therapy to prevent gastric irritation in patients at high risk for GI bleed) affect platelet inhibition by clopidogrel. We hypothesis that platelet activity following clopidogrel will be significantly lower in CYP2C19 wt/wt patients with co administration of rabeprazole compared to omeprazole and lower still following ranitidine due to different CYP2C19 metabolism profiles of these antacids.;Secondary Objective: To assess the gastrin hormone (surrogate for stomach pH) of different gastroprotective agents to determine antacid efficacy during dual antiplatelet therapy.;Primary end point(s): Difference in platelet aggregation measured by VerifyNow after omeprazole, rabeprazole and ranitidine in extensive metabolisers (wt/wt CYP2C19) treated with clopidogrel for 7 days.	—

Measure

Time frame

Main Objective: To study platelet activity using the bed-side VerifyNow assay to determine whether different gastroprotective agents (prescribed with dual anti-platelet therapy to prevent gastric irritation in patients at high risk for GI bleed) affect platelet inhibition by clopidogrel. We hypothesis that platelet activity following clopidogrel will be significantly lower in CYP2C19 wt/wt patients with co administration of rabeprazole compared to omeprazole and lower still following ranitidine due to different CYP2C19 metabolism profiles of these antacids.;Secondary Objective: To assess the gastrin hormone (surrogate for stomach pH) of different gastroprotective agents to determine antacid efficacy during dual antiplatelet therapy.;Primary end point(s): Difference in platelet aggregation measured by VerifyNow after omeprazole, rabeprazole and ranitidine in extensive metabolisers (wt/wt CYP2C19) treated with clopidogrel for 7 days.

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Countries

United Kingdom

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026