Plain English Summary
Background and study aims
Women who have given birth, especially those who have had a Caesarean section, are at risk of developing deep vein thrombosis (DVT). DVT is where a blood clot develops in a deep vein in one or both of the legs, causing pain, swelling and long term complications such as leg ulcers. In order to avoid this, these women are usually given injections of a drug called heparin (a blood thinner) for up to 7 days after delivery. If a mother is taking heparin, it is considered safe for the baby as it does not pass into breast milk. Most women are discharged before 7 days after delivery and need to continue doing the injections themselves at home. This involves taking the sharps home, and many women find it difficult and inconvenient and there is evidence to suggest that many women do not take the injections at all. Dabigatran is a blood thinning drug that can be swallowed as a hard capsule. It is currently licenced in the UK for other situations including the prevention of blood clots after hip/knee replacement surgery. It is currently not known whether this drug would pass into breast milk after it has been taken by the mother and therefore safe for the baby. The aim of this study is to find out whether dabigatran capsule could be used instead of heparin injections for new mothers by finding out if it passes into breast milk.
Who can participate?
Women who have given birth who have made the decision not to breastfeed their baby.
What does the study involve?
All participants are given two 110mg capsules of dabigatran to take. A total of seven samples of breast milk (15ml each) and blood (15ml) are then taken immediately, 1, 2, 3, 5, 7 and 10 hours after the capsules have been taken. The samples are then tested in the lab in order to find out the amount of dabigatran present in each.
What are the possible benefits and risks of participating?
There are no direct benefits to participants taking part in this study. There is a small risk of pain and discomfort during the taking of blood samples from participants . Additionally, there is a very small risk of bleeding when taking dabigatran, however all participants be in hospital for the treatment visit and extra safety tests will be done before the drug is given in order to avoid complications.
Where is the study run from?
Newcastle Clinical Trials Unit (UK)
When is the study starting and how long is it expected to run for?
February 2016 to August 2016
Who is funding the study?
National Institute for Health Research (UK)
Who is the main contact?
Miss Jean Walker
An Open Label, Non-Randomised, Phase II study to Determine if Dabigatran and its Metabolites are Detectable in Breast Milk Following Oral Administration to Non-Breastfeeding Mothers
The aim of this study is to find out if a dabigatran capsule could be used instead of heparin injections to reduce the risk of deep vein thrombosis in new mothers.
North East - Tyne & Wear South Research Ethics Committee, 11/11/2015, ref: 15/NE/0331
Open-label non-randomised phase II study
Primary study design
Secondary study design
Non randomised study
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Topic: Children, Reproductive Health; Subtopic: Children (all Diagnoses), Reproductive Health & Childbirth (all Subtopics); Disease: All Diseases, Reproductive Health & Childbirth
The study duration is 12 months, including a recruit period of 7 months in which to consent 10 women. All eligible and enrolled women will receive a single oral dose of a 110mg dabigatran capsule, swallowed with water. Participants will be asked to complete a 10 hour treatment visit to provide up to 7 expressed breast milk samples and 7 blood samples. Each participant will be supported by the research midwife and additional support offered from the Infant Feeding Coordinator for up to 2 weeks following expression. The last follow up contact at 2 weeks will be the end of the study for the participants, after which their routine post-natal clinical care will continue.
Primary outcome measure
Dabigatran presence in plasma and breast milk is measured at baseline, 1, 2, 3, 5, 7, 10 hours.
Secondary outcome measures
1. Presence of dabigatran metabolites in breast milk is measured at baseline, 1, 2, 3, 5, 7, 10 hours
2. Time course of dabigatran concentration in breast milk is measured at baseline, 1, 2, 3, 5, 7, 10 hours
3. Time course of dabigatran concentration in maternal plasma is measured at baseline, 1, 2, 3, 5, 7, 10 hours
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Women aged 18 years and over
2. Woman has had a vaginal birth (spontaneous or instrumental)
3. Minimum of 48 hours has passed after delivery of the baby/removal of epidural catheter or spinal anaesthesia
4. Minimum of 24 hours has passed after the decision has been made and documented in the notes to stop breast feeding the baby after starting/trying to start
5. Hospital inpatient
6. Woman has been offered the opportunity to have a discussion at delivery and in the immediate postnatal period in relation to their feeding choices using the Feeding Your Baby booklet
7. Decision has been confirmed by the woman to exclusively formulafeed her baby (including women who have since decided to stop breastfeeding their baby)
8. Midwife has confirmed the decision with the woman and has documented this in the Feeding Your Baby Booklet held in the medical notes.
9. Normal renal function test – results of the serum creatinine <90 micro mol/L
10. Normal liver function tests – results of the serum ALT </= 40 IU/L
11. Not taking any medication except paracetamol and / or dihydrocodeine. Women who have been given ibuprofen for pain relief after delivery can be included at least 24 hours after the last dose. Women will be advised not to take nonsteroidal antiinflammatory drugs (aspirin, ibuprofen, diclofenac, naproxen, indometnacin) for at least 3 days after taking the study treatment)
12. Participant has provided written informed consent for participation in the study before any study specific procedures take place
Target number of participants
Planned Sample Size: 10; UK Sample Size: 10
Total final enrolment
Participant exclusion criteria
1. Women who are planning to/are breastfeeding
2. Women who are planning to/giving their baby expressed breast milk
3. Women who are unsure of their decision to breast feed or formula feed
4. Women who are unable to provide written informed consent
5. LMWH thromboprophylaxis is indicated
6. Increased risk of bleeding for any reason
7. An increased tendency to bleed (inborn, of unknown cause or due to other medications)
8. Known contraindications to dabigatran
9. Ongoing treatment with aspirin, NSAIDs or other drugs that affect haemostasis
10. Treatment with oral ketoconazole or itraconazole, medicines to treat fungal infections
11. Patients who have received an artificial heart valve, have had a heart attack or suffer an irregular heartbeat (including taking dronedarone)
12. Known impaired renal function (serum creatinine > 90 micro mol/L)
13. Known abnormal liver function tests (ALT > 40 IU/L)
14. Known hypersensitivity or allergy to dabigatran
15. Use of other investigational study drugs within 30 days prior to study entry
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Newcastle Clinical Trials Unit
Newcastle University 1-4, Claremont Terrace
Newcastle upon Tyne
Boehringer Ingelheim Ltd
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication on the detection of dabigatran and its metabolites in breast milk following single oral dose in non-breastfeeding mothers.
Intention to publish date
Participant level data
Not expected to be available
Basic results (scientific)
See: https://www.clinicaltrialsregister.eu/ctr-search/trial/2014-004249-29/results (added 21/06/2019)