Rivaroxaban Effects in Subjects Who Have Undergone Gastric Bypass Surgery

Study Overview
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Brief Summary
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The investigators are attempting to compare the anticoagulant (blood thinning) effects of a recently FDA approved medication, Rivaroxaban, in people who have undergone gastric bypass surgery to people who have not had this surgery. It is thought that gastric bypass may alter the absorption of this medication, but this has not been previously studied. The investigators will study the anticoagulant effect of rivaroxaban in healthy volunteers who are in one of four groups Non obese people who have not had a gastric bypass. Obese people who have not had a gastric bypass People who have had a gastric bypass People who are planning to undergo gastric bypass surgery in the near future who are willing to be studied before and after the bypass. The study will involve taking a single low dose of rivaroxaban and multiple blood samples will be taken over the next 24 hours and the effect of rivaroxaban on blood clotting will be measured using the prothrombin time and an anti-factor Xa assay. The effects of rivaroxaban will be compared between the different groups.

Official Title
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A Pharmacodynamic Study of Rivaroxaban in Subjects Who Have Undergone Roux-en-Y Gastric Bypass Surgery

Conditions
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Gastric Bypass Status

Intervention / Treatment
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* Drug: rivaroxaban


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers in one of four groups Normal weight and not having prior gastric bypass surgery, Obese and not having prior gastric bypass surgery, Subjects with prior roux en Y gastric bypass surgery, Obese and planning to undergo roux en Y gastric bypass Exclusion Criteria: Active renal or liver disease, bleeding diathesis, concurrent treatment with anticoagulants or aspirin, indication for aspirin or anticoagulant treatment, gastrointestinal bleeding, uncontrolled hypertension, active malignancy, anemia, thrombocytopenia, pregnant, allergy to rivaroxaban, coagulopathy or any other medical condition that would increase risk to the subject

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: normal subjects<br>A single dose of 10 mg of rivaroxaban will be administered | Drug: rivaroxaban<br>* Single dose pharmacodynamic study<br>* Other names: Xarelto;|
| Experimental: Obese non bypassed<br>A single dose of rivaroxaban will be administered | Drug: rivaroxaban<br>* Single dose pharmacodynamic study<br>* Other names: Xarelto;|
| Experimental: obese bypassed<br>A single dose of rivaroxaban will be administered | Drug: rivaroxaban<br>* Single dose pharmacodynamic study<br>* Other names: Xarelto;|
| Experimental: pre and post bypassed subject<br>A single dose of rivaroxaban will be administered prior to gastric bypass. Subjects will be restudied 12 to 24 weeks following bypass | Drug: rivaroxaban<br>* Single dose pharmacodynamic study<br>* Other names: Xarelto;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| median inhibition of factor xa inhibition | pharmacodynamic | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| median prolongation of prothrombin time | pharmacodynamic | 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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gastric bypass, rivaroxaban, pharmacodynamics