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A 59-year-old female asked:

Can lasix affect inr coumadin level? my 84 year old mother is on coumadin theropy (has st judes valve) it has been in the inr targeted range of 2.5-3.5 but today it was 8.0...we do home testing and checked it twice. she lives alone and has a terrible m

2 doctor answers2 doctors weighed in
Dr. John Fung
General Surgery 40 years experience
According : According to drugs.Com, Lasix (furosemide) may displace warfarin from plasma protein binding sites. Plasma warfarin concentrations and warfarin effects may be increased. This interaction is characterized as minor clinical importance. However, everything else being the same, and that she did not confuse her Lasix (furosemide) with Coumadin and take more Coumadin than thought, then this interaction may have contributed to the increased inr. In any case, this is too high and if she is bleeding, or altered mental status or paralysis, she should be sent to the hospital for evaluation and treatment. However if she is stable, hold the Coumadin and retest her inr. She can resume taking her dose when the inr is less than 5.0. In addition, her physician should be notified of this change.
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Dr. Alvin Lin
Geriatrics 31 years experience
Dr. : Dr. Fong makes some excellent points. Having lived in nc for about a quarter of my life, i used to ask my patients if they had changed the amount of collards they'd consumed. Leafy greens are high in vitamin k which is antagonized by warfarin. So while many clinics might suggest that patients taking warfarin avoid eating greens, this seems more like the tail wagging the dog. Instead, i suggest that they find an amount that they can consume regularly and adjust the warfarin dose accordingly. And when it's collard season, they should get their pt/inr checked more frequently and make adjustments as necessary. However, this assumes that someone has intact cognitive function or a caregiver to take responsibility. In your case, i worry that your mother might have some form of dementia that might increase her likelihood of an untoward event should she vary her amount of greens/collards or mistake her lasix/warfarin. Check w/her family physician about the possibility of home health services and meals on wheels programs. Good luck!
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Jun 29, 2017


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