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Saint Paul, MN
A 47-year-old female asked:

Is it still possible to get blood clots (dvt, pe) while on warfarin? have factor v leiden. suffered dvt and pe 18 months ago. inr 2.5 last check.

3 doctor answers6 doctors weighed in
Dr. Robert Killian
General Practice 30 years experience
Warfarin: Yes, but only if the therapeutic inr range is not ideal. At 2.5 you are perfect and the risk for clots diminishes at this level.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Thomas Wright
Phlebology 31 years experience
Yes it can occur : It is very unlikely to have a DVT when on warfarin at a therapeutic level inr 2.5 , but it does happen. Usually there are multiple risk factor involved : such as factor v , plus recent DVT , plus some other risk factors, or possibly just being homozygous [ a mutation in both alleles of factor v leiden]. So it is rare but can happen . I hope this helps.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Alex Spyropoulos
Internal Medicine 31 years experience
Warfarin failures: Warfarin failure syndromes while in the therapeutic range are uncommon and occur ~1-2% of patients per year. They are less likely due to thrombophilic conditions and more due to highly inflammatory or thrombogenic conditions such as cancer or anti phospholipid syndrome. There are new oral anticoagulants such as rivaroxaban and dabigatran that are FDA approved for VTE and do not require monitoring
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Thomas Wright
Phlebology 31 years experience
Dr Spyropoulos ,that is a good point that therapeutic failures are more like due to cancer and other inflammatory conditions .
May 27, 2014
Dr. Alex Spyropoulos
Internal Medicine 31 years experience
Provided original answer
Yes. The other thing I failed to mention that I see most commonly with "warfarin failure syndromes" as Director of large anticoagulation clinics is not so much failure of warfarin but failure in the way warfarin is managed i.e. quality of warfarin control, as reflected by low time spent in therapeutic range or TTR (< 50%). TTR may become a new CMS measure in near future.
May 27, 2014
Last updated Dec 29, 2022

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