A Phase 1 interventional study of omeprazole and pantoprazole in Drug Interaction, sponsored by University of Florida. Completed at 1 site in United States. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2012-03-06.
Sponsored by University of Florida · Phase 1 and Interventional
Clopidogrel, in combination with aspirin, is currently the recommended treatment for secondary prevention of ischemic events in high-risk patients and for prevention of coronary artery stent thrombosis. Patients receiving aspirin and clopidogrel are frequently treated with proton pump inhibitors, such as omeprazole or pantoprazole, in order to prevent the risk of gastrointestinal bleeding, accorded to guidelines. An interaction between proton pump inhibitors and clopidogrel has been suggested, which may lead to a decrease of clopidogrel effects. It remains unclear whether this interaction between PPIs and clopidogrel might be a class effect or if this may be affected by timing regimen.
The objectives of this two-phase investigation are:
Clopidogrel, in combination with aspirin, is currently the recommended treatment for secondary prevention of ischemic events in high-risk patients and for prevention of coronary artery stent thrombosis. Patients receiving aspirin and clopidogrel are frequently treated with proton pump inhibitors, such as omeprazole or pantoprazole, in order to prevent the risk of gastrointestinal bleeding, accorded to guidelines. An interaction between proton pump inhibitors and clopidogrel has been suggested, which may lead to a decrease of clopidogrel effects. It remains unclear whether this interaction between PPIs and clopidogrel might be a class effect or if this may be affected by timing regimen. The objectives of this two-phase investigation are: 1. to compare clopidogrel platelet inhibitory effects when taken at the same time versus separated at least 8 hours from omeprazole administration. 2. to compare clopidogrel-induced inhibitory effects when taken at the same time versus staggered at least 8 hours from pantoprazole administration. The clopidogrel dose will be a 600mg loading dose followed by a 75mg daily maintenance dose, starting the next day for 7 days. Omeprazole will be used at a daily dose of 40mg and pantoprazole at 80mg.
The proposed study will have a prospective, randomized, cross-over design. Subjects are randomized in a 1:1 fashion to take PPI concomitantly (CONC regimen) or staggered by 8-12 hours (STAG regimen) for one-week on a background of clopidogrel therapy. In particular, in the CONC regimen both drugs were taken in the morning, while in the STAG regimen clopidogrel was taken in the morning and omeprazole in the evening. After a 2-4 week washout period, subjects crossed-over treatment regimen. After completing these two treatment phases, subjects underwent another washout period of 2-4 weeks and were treated for 1 week with clopidogrel alone, without receiving omeprazole therapy (CLOP regimen). The sequence with the PPI pantoprazole will have the same prospective, randomized, cross-over design as the omeprazole sequence. A CLOP regimen in the absence of pantoprazole will be collected before entering randomization phase with adequate wash-out period.
Blood sampling for platelet function assessments were performed at all three phases of the study at the following time points: a) baseline, b) 24 hours after LD (before intake of study medication), and c) 7 days (24 hours after the last MD).
University of Florida is the lead sponsor of 1,285 studies on the registry; 199 are open to participants now.
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Exclusion Criteria:
prospective, open-label, two-sequence, three-period, randomized crossover study
Drug: omeprazole and pantoprazole
prospective, open-label, two-sequence, three-period, randomized crossover study
Drug: omeprazole and pantoprazole
The clopidogrel dose will be a 600mg loading dose followed by a 75mg daily maintenance dose, starting the next day for 7 days. Omeprazole will be used at a daily dose of 40mg and pantoprazole at 80mg.
Platelet Function as Assessed by the P2Y12 Reactivity Index
P2Y12 reactivity index which will be assessed by flow cytometry determination of vasodilator-stimulated phosphoprotein (VASP).
Time frame: 1 week
| Milestone | Omeprazole | Pantoprazole |
|---|---|---|
| Started | 20 | 0 |
| Completed | 20 | 0 |
| Not completed | 0 | 0 |
| Milestone | Omeprazole | Pantoprazole |
|---|---|---|
| Started | 0 | 20 |
| Completed | 0 | 20 |
| Not completed | 0 | 0 |
P2Y12 reactivity index which will be assessed by flow cytometry determination of vasodilator-stimulated phosphoprotein (VASP).
| Percentage of platelet reactivity index | Omeprazole Concomitant | Omeprazole Staggered | Pantoprazole Concomitant | Pantoprazole Staggered | Clopidogrel Only (Omeprazole Phase) | Clopidogrel Only (Pantoprazole Phase) |
|---|---|---|---|---|---|---|
| Platelet Function as Assessed by the P2Y12 Reactivity Index | 56.1 ± 3.5 | 61.6 ± 3.4 | 56 ± 3.9 | 61 ± 3.9 | 48.8 ± 3.4 | 61.0 ± 3.9 |
Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Omeprazole | — | 0/20 (0%) | 0/20 (0%) |
| Pantoprazole | — | 0/20 (0%) | 0/20 (0%) |
| Age, Categorical(Participants) | All Study Participants |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 25 |
| >=65 years | 0 |
| Age Continuous(years) | All Study Participants |
|---|---|
| Omeprazole cross-over n=20 | 34 ± 6 |
| Pantoprazole cross-over n=20 | 33 ± 5 |
| Sex: Female, Male(Participants) | All Study Participants |
|---|---|
| Female | 0 |
| Male | 25 |
| Region of Enrollment(participants) | All Study Participants |
|---|---|
| United States | 25 |
The record gives a start of Mar 2009, a primary completion of Aug 2010 and a completion of Aug 2010. It does not say whether these dates are actual or estimated.
Results were first posted in Mar 2012, 1 year 7 months after primary completion.
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