AnticoagulationPhase 1NCT01124058
Evaluation of Maintenance Dosing vs Loading Dosing Upon Restarting Warfarin Therapy: A Prospective Randomized Trial
A Phase 1 study testing warfarin in people with Anticoagulation, run by University of Alberta at 1 site in Canada.
Trial summary
A prospective, randomized trial to compare the time taken to achieve a therapeutic INR upon re-starting warfarin at a "loading" dose (namely 1.5 times the "maintenance" dose for 3 days) compared to the known "maintenance" dose. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anticoagulation
- What is being tested?
- warfarin
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 39 participants
- Where
- 1 siteCanada
- Study dates
- Jul 2010to Aug 2012
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Have 'stable warfarin maintenance dosing' (defined as last 2 INRs within therapeutic range with weekly warfarin dosing not being changed any more than 10%)
- Have an INR indicative of not taking any warfarin (INR <1.4) or confirmation of the patient not taking any warfarin in the past 4 days
- Provide written, informed consent
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Maintenance Dosing vs Loading Dosing Upon Restarting Warfarin Therapy: A Prospective Randomized Trial.
A prospective, randomized trial to compare the time taken to achieve a therapeutic INR upon re-starting warfarin at a "loading" dose (namely 1.5 times the "maintenance" dose for 3 days) compared to the known "maintenance" dose.
Read the detailed description
Patients will be identified via the University of Alberta Hospital Anticoagulation Management Service. Following the receipt of written, informed consent, patients will be randomized to re-start warfarin at their "maintenance" dose or at a "loading" dose (1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose). Randomization will be performed on-line through the EPICORE Centre.
Assuming Day 1 is the day warfarin is re-started, patients will have INRs done on day 3 and at least every 2 days thereafter until a therapeutic INR is obtained. In addition, protein C, protein S and factor II levels will be obtained while the patient is on stable maintenance dosing of warfarin (i.e., prior to holding warfarin for the procedure), 7 days after re-starting warfarin, and 14 days after re-starting warfarin. Complete blood counts (CBCs) will be done with each INR if the patient is taking a low molecular weight heparin (LMWH). Patients will have their anticoagulant therapy managed by the AMS for 6 weeks and will receive a telephone follow-up by the AMS at 90 days to determine if any bleeding or clotting complications occurred.
- Conditions
- Anticoagulation
- Being tested
- warfarin
- Keywords
- restarting warfarin, time to therapeutic INR
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
warfarinDrug
Also called warfarin, Taro-warfarin, Apo-warfarin, Coumadin, Fragmin, Low-molecular weight heparin
Patients will be randomized to re-start warfarin at their "maintenance" dose or at a "loading" dose (1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose).
WarfarinDrug
Also called warfarin, Taro-warfarin, Apo-warfarin, Coumadin, Fragmin, Low-molecular weight heparin
"Maintenance" dose is the amount of warfarin that a patient required to maintain a therapeutic INR.
| Study group | Role | What they receive |
|---|---|---|
| Loading | Experimental | 1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose Receives: Drug: warfarin |
| Maintenance | Active comparator | Re-start same dose as previously stable on Receives: Drug: Warfarin |
What is being measured
The primary outcome is the main question the study is designed to answer.
re-starting warfarin "loading" dose vs "maintenance" dose
To compare the time taken to achieve a therapeutic INR between those patients re-starting warfarin with a "loading" dose and a "maintenance" dosing regimen using linear interpolation of INRs.
Measured: INR drawn 3 days post-reinitiation and then every 2 days until therapeutic
Secondary outcomes (3)
Compare % of time within, above and below the target INR range
To compare the % of time within, above and below the desired INR range between those patients re-starting warfarin with a "loading" dose or "maintenance" dose 6 weeks following restarting warfarin.
Measured: days
Compare bleeding/clotting complications between two groups
To compare the rates of thrombosis (i.e., stroke) / major hemorrhage between those re-starting warfarin with a "loading" dose or "maintenance" dose at 30 days and 90 days following restarting warfarin.
Measured: 30 days, 90 days
Compare the levels of protein C, protein S, and factor II between 2 groups.
To compare the levels of protein C, protein S, and factor II between those re-starting warfarin with a "loading" dose or "maintenance" dose.
Measured: week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 May 2010 (estimated)
- Study startJul 2010
- Primary completionAug 2012
- Study completionAug 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnticoagulationStudies of the same condition, open and under way.
- More trials run by University of AlbertaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 39 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Alberta
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tammy Bungard, University of Alberta
- Investigators
- Tammy J Bungard, BSP, PharmD, Principal investigator, Univeristy of AlbertaBruce Ritchie, MD, FRCPC, Principal investigator, University of Alberta
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01124058
- Sponsor's protocol ID
- 2007UHFMDvsLD
- Status last verified
- Oct 2017
- First submitted
- 13 May 2010
- Last updated
- 25 Oct 2017
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Oct 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Maintenance Dosing vs Loading Dosing Upon Restarting Warfarin Therapy: A Prospective Randomized Trial.
- ClinicalTrials.gov ID
- NCT01124058
- Acronym / sponsor ID
- 2007UHFMDvsLD
- Conditions
- Anticoagulation
- Keywords
- restarting warfarin, time to therapeutic INR
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 39 participants (actual)
- Lead sponsor
- University of AlbertaUniversity, hospital or other
- Study start
- Jul 2010 (actual)
- Primary completion
- Aug 2012 (actual)
- Study completion
- Aug 2012 (actual)
- First posted
- 14 May 2010 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A prospective, randomized trial to compare the time taken to achieve a therapeutic INR upon re-starting warfarin at a "loading" dose (namely 1.5 times the "maintenance" dose for 3 days) compared to the known "maintenance" dose.
Detailed description
Patients will be identified via the University of Alberta Hospital Anticoagulation Management Service. Following the receipt of written, informed consent, patients will be randomized to re-start warfarin at their "maintenance" dose or at a "loading" dose (1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose). Randomization will be performed on-line through the EPICORE Centre.
Assuming Day 1 is the day warfarin is re-started, patients will have INRs done on day 3 and at least every 2 days thereafter until a therapeutic INR is obtained. In addition, protein C, protein S and factor II levels will be obtained while the patient is on stable maintenance dosing of warfarin (i.e., prior to holding warfarin for the procedure), 7 days after re-starting warfarin, and 14 days after re-starting warfarin. Complete blood counts (CBCs) will be done with each INR if the patient is taking a low molecular weight heparin (LMWH). Patients will have their anticoagulant therapy managed by the AMS for 6 weeks and will receive a telephone follow-up by the AMS at 90 days to determine if any bleeding or clotting complications occurred.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Loading | Experimental | Drug: warfarin1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose |
| Maintenance | Active comparator | Drug: WarfarinRe-start same dose as previously stable on |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Have 'stable warfarin maintenance dosing' (defined as last 2 INRs within therapeutic range with weekly warfarin dosing not being changed any more than 10%)
- Have an INR indicative of not taking any warfarin (INR <1.4) or confirmation of the patient not taking any warfarin in the past 4 days
- Provide written, informed consent
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| warfarinAlso: warfarin, Taro-warfarin, Apo-warfarin, Coumadin, Fragmin, Low-molecular weight heparinPatients will be randomized to re-start warfarin at their "maintenance" dose or at a "loading" dose (1.5 times the maintenance dose for 3 days, then resumption of warfarin dosing as per the maintenance dose). | Drug | Loading |
| WarfarinAlso: warfarin, Taro-warfarin, Apo-warfarin, Coumadin, Fragmin, Low-molecular weight heparin"Maintenance" dose is the amount of warfarin that a patient required to maintain a therapeutic INR. | Drug | Maintenance |
Primary outcome
re-starting warfarin "loading" dose vs "maintenance" dose
Time frame: INR drawn 3 days post-reinitiation and then every 2 days until therapeutic
To compare the time taken to achieve a therapeutic INR between those patients re-starting warfarin with a "loading" dose and a "maintenance" dosing regimen using linear interpolation of INRs.
3 secondary outcomes
Compare % of time within, above and below the target INR range
Time frame: days
Compare bleeding/clotting complications between two groups
Time frame: 30 days, 90 days
Compare the levels of protein C, protein S, and factor II between 2 groups.
Time frame: week
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Oct 2017.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Tammy J Bungard, BSP, PharmD principal investigator
Univeristy of Alberta
Bruce Ritchie, MD, FRCPC principal investigator
University of Alberta
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing warfarin in people with Anticoagulation, run by University of Alberta at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Oct 2017. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
re-starting warfarin "loading" dose vs "maintenance" dose (time frame: INR drawn 3 days post-reinitiation and then every 2 days until therapeutic). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Oct 2017.