Reducing Gastrointestinal Bleeding With Proton Pump Inhibitor Therapy in Acute Venous Thromboembolism

Inclusion Criteria: 1. Male or female 65 years or older at the time of enrolment. Enrolment is limited to older adults as age is an important non-modifiable risk factor for bleeding. This will ensure the study population includes participants who may be more likely to benefit from omeprazole (compared to those with no risk factors) because all participants will have at least 1 risk factor for bleeding. 2. Newly diagnosed VTE which includes VTE at any site such as (but not limited to) DVT of upper or lower limbs, PE, cerebral vein thrombosis, portal vein thrombosis, other splanchnic vein thrombosis. 3. Planned for 3 months (90 days) or more of therapeutic anticoagulation with any anticoagulant. 4. Patient or delegate is able and willing to comply with follow-up examinations contained within the consent form. Exclusion Criteria: 1. Therapeutic anticoagulation therapy for more than 7 days 2. Currently prescribed PPI for regular daily use (patients receiving H2 receptor antagonists will not be excluded), 3. Previous upper GI bleeding, 4. Need for dual antiplatelet therapy, 5. Contraindications to omeprazole (hypersensitivity to omeprazole, or other substituted benzimidazole PPIs, concomitant use with products that contain rilpivirine, significant drug interactions, up to the discretion of the site investigator), 6. Life expectancy is less than 3 months.