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Study on the Effects of Apixaban Absorption in Patients Undergoing Roux-en-Y Gastric Bypass Surgery

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on patients who have undergone a Roux-en-Y gastric bypass, a type of weight-loss surgery. The study is examining how this surgery affects the absorption of a medication called Apixaban, which is a blood thinner used to prevent blood clots. The trial will also involve other medications, including Beriplex, Norit, and Ondexxya, which are used as reversal agents to counteract the effects of blood thinners.

The purpose of the study is to understand how the body processes Apixaban before and after the surgery. Participants will receive the medication and have their blood levels checked at different times: before the surgery, shortly after, and a few months later. This will help researchers see how the surgery impacts the medication's effectiveness. The study will also monitor participants' weight and body mass index (BMI) changes, as well as any major bleeding events or occurrences of blood clots, such as pulmonary embolism or deep vein thrombosis.

The study is expected to run until 2026, with recruitment starting in 2025. Participants will be closely monitored throughout the study to ensure their safety and to gather important data on how Roux-en-Y gastric bypass surgery affects the absorption and effectiveness of Apixaban and other related medications.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment will be conducted to confirm eligibility. This includes verifying that you are 18 years or older and have been approved for a laparoscopic gastric bypass surgery.

  2. Step 2

    Baseline measurement

    Before the surgery, a baseline measurement of your blood levels will be taken. This involves measuring the Area Under the Curve (AUC) of anti-Xa levels, which helps in understanding how the medication apixaban is absorbed in your body.

  3. Step 3

    Surgery

    You will undergo the Roux-en-Y gastric bypass surgery as planned. This is a surgical procedure to help with weight loss.

  4. Step 4

    Post-surgery medication

    After the surgery, you will continue to take apixaban orally. The dosage and frequency will be as prescribed by your healthcare provider.

  5. Step 5

    Follow-up measurements

    Follow-up measurements of the AUC of anti-Xa levels will be conducted at multiple time points: approximately 17 days after surgery, up to 60 days after surgery, and around 3 months after surgery. These measurements help in assessing the changes in medication absorption post-surgery.

  6. Step 6

    Weight and BMI check

    At the 3-month follow-up visit, your weight and Body Mass Index (BMI) will be measured to evaluate the weight-loss effects of the surgery.

  7. Step 7

    Monitoring for side effects

    Throughout the study, you will be monitored for any major bleeding events and the occurrence of venous thromboembolism (VTE), which includes conditions like pulmonary embolism and deep vein thrombosis.

Who can join the trial?

2 criteria

  • Patients who are screened and approved to undergo laparoscopic gastric bypass (a type of weight-loss surgery).
  • Age 18 years or older.

Who cannot join the trial?

3 criteria

  • Patients who have not undergone a Roux-en-Y gastric bypass surgery. This is a type of weight-loss surgery that changes the structure of the stomach and small intestine.
  • Patients who are not within the specified age range for the study.
  • Patients who are part of a vulnerable population, which means they might need special protection or care.
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  • Verified

    Amsterdam UMC

    The NetherlandsAmsterdam, The Netherlands

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Investigated drugs

Apixaban is a medication used to prevent blood clots. It is often prescribed to people who have conditions that increase their risk of developing clots, such as atrial fibrillation, a type of irregular heartbeat. In this clinical trial, the researchers are studying how the body absorbs and processes apixaban before and after a specific type of weight-loss surgery called Roux-en-Y gastric bypass. This surgery changes the digestive system, and the study aims to understand if and how it affects the way apixaban works in the body.

What is already known about the treatment

Apixaban – Apixaban is a medication taken orally, usually in the form of a tablet, and is used to prevent blood clots. It is currently well-established in medical practice and literature as an anticoagulant, particularly for patients who have undergone procedures like Roux-en-Y gastric bypass. The main therapeutic use of apixaban is to reduce the risk of stroke and blood clots in people with certain heart conditions or after surgery. At the molecular level, apixaban works by inhibiting a specific protein in the blood called Factor Xa, which is crucial for blood clot formation. It belongs to a class of drugs known as direct oral anticoagulants (DOACs).

Investigated diseases

Obesity – Obesity is a condition characterized by excessive body fat accumulation that may impair health. It develops when calorie intake consistently exceeds calorie expenditure, leading to an energy imbalance. Over time, this results in an increase in body weight and body mass index (BMI). Obesity can progress gradually, often starting with weight gain and eventually leading to a state where the body has a high percentage of fat. It is associated with various metabolic changes and can contribute to the development of other health conditions. The progression of obesity can vary based on lifestyle, genetics, and environmental factors.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-519737-30-00Estimated enrolment30 patientsSponsorAmsterdam UMC Stichting

sourced from the EU Clinical Trials Register and site verification

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