Time of day for warfarin dose?

[Marty]

To my knowledge we have not discussed recently whether it is best to take warfarin in AM at breakfast or later after supper or at bed time. For years I took warfarin early AM. My wife Alice was advised to take at bedtime. The ACT nurse in her cardiologists office said "warfarin works better at night!". What is the latest thinking about this? I tried to switch to late evening but forgot a couple of times and am now back to AM

 

[Ross]

It makes no difference. Usually, the Doctors want you to take it at night so they can make dose adjustments during the day. That is the only reason for taking it at night. Searching papers on Google yields the same reason. Doctor convenience of dose changes. No other reasons.

I take mine first thing in the morning when making coffee or as sure as the sun comes up, I'll forget.

 

[Marty]

It makes no difference. Usually, the Doctors want you to take it at night so they can make dose adjustments during the day. That is the only reason for taking it at night. Searching papers on Google yields the same reason. Doctor convenience of dose changes. No other reasons.

I take mine first thing in the morning when making coffee or as sure as the sun comes up, I'll forget.

Thanks, Ross. I think this is the best and only answer!

 

[Bina]

Hospitals tend to give it at dinner time.....5:00 or 6:00 pm with the meal.
That has always worked for me. And if I should every miss it, then it will be discovered in my pill box when I go to take my evening beta blocker.
Also, I test my INR in the afternoon, so any dosage changes can be made a couple of hours later instead of the next morning.
This topic has crept into several threads the last few months, and we all have different routines.

 

[sue943]

6pm works for me too, that is when I was told to take it and have continued so to do.

 

[Eva]

I take my Warfarin at night and I test my INR around 11 am. Last time my INR was very low, I took the extra mgs (adjustment) right away to push my INR a bit up and took my usual dose at night as routine!! I hated stay all day with a low INR until the evening.!!!!!

Anyone, correct me if that was wrong!

 

[Ross]

I take my Warfarin at night and I test my INR around 11 am. Last time my INR was very low, I took the extra mgs (adjustment) right away to push my INR a bit up and took my usual dose at night as routine!! I hated stay all day with a low INR until the evening.!!!!!

Anyone, correct me if that was wrong!

Can't say if your right or wrong without more info. Do you have any idea why it would have come up low?

Just remember, it doesn't matter if you increase the dose as it's still going to take 3 days to show. Taking 10mg today if you normally take 5 is only going to make you overshoot in the end.

 

[Eva]

Ross,

Strangely, that was a week after (it just happened) I did not have any greens, no hummus nor any of the food with some K vitamin which I normally eat!!

[by the way, where are you going to!? walking and walking and walking???!!!!]

 

[Ross]

I'm off to rescue whomever needs it. Need my people to help. Indiana Jones and the kitty to make me roll.

Have you been trending downward prior to this big drop?

 

[Eva]

I'm off to rescue whomever needs it. Need my people to help. Indiana Jones and the kitty to make me roll.Good luck

Have you been trending downward prior to this big drop?

in the past, on and off but steady the lat few weeks prior to this drop off

 

[Ross]

Then increase your dose by 5 or 10% and retest in 4 days.

 

[dick0236]

Marty, like Ross says, it makes no difference when Warfarin is taken. I have always taken it in the morning because that has been the most convenient time for me. The important thing is to establish a routine of taking it at the same time each day.... morning, noon or night.

 

[Nancy]

The hospital always gave Joe his right before dinner. He was also told to take it in the evening, and did so religiously along with his evening pills, right before dinner. It was so routine that he rarely forgot.

 

[ALCapshaw2]

Just remember, it doesn't matter if you increase the dose as it's still going to take 3 days to show.

Ross,

Can you quote a Source for that Theory?

Personally, I find it difficult to comprehend.

The notion that NOTHING Happens for 3 days and then 'magically' you get the FULL EFFECT of the Coumadin/Warfarin all-at-once is Scientifically Incomprehensible to me.

To my mind, it is analogous to saying than an aneurism is Safe up to 4.9 cm but at High Risk of Rupture at 5.0 which we KNOW is Not True.

Again, to my mind, it makes more sense that the Warfarin/Coumadin is metabolized SLOWLY and is Finally Fully Metabolized after 3 or 4 days.

Can anyone provide a reference that describes the complete cycle of Warfarin metabolization and subsequent effect on INR? It would be interesting to see a plot of INR vs Time given a constant daily dose of Warfarin.

'AL Capshaw'

(Edited and supplemented version)

 

[Bridgette]

I take my Warfarin just before I go to bed. The nurses at the hospital said it didn't really matter what time of day I took it, just to make sure that I was consistent and took it at the same time every day.

 

[ctyguy]

I take mine before I go to bed. Coumadin Clinic told me that if I forget to take it and notice in the AM then to take in right away. They said if your within 12 hours of your scheduled time then to take your dose and not to worry. I have missed my evening dose a few times, noticing it when getting ready in the mornings. At least this way I have a chance to stay on track.

 

[Bina]

in the past, on and off but steady the lat few weeks prior to this drop off

Eva, you may have noticed a change this past week because of your travelling.....(?)

 

[ALCapshaw2]

Bina,

When you were having your INR checked every day after surgery, did you save a copy of the dosing and INR records for that time period?

That would provide an interesting historical record of the effect of Coumadin / Warfarin starting from an INR of 1.0 up to Theraputic Range.

'AL Capshaw'

 

[Bina]

Yes Al, I have the records, and my INR did bounce a bit because they started me on 5mg and I only needed half of that.
It took 16 days before they would let me leave with a good INR.
Maybe tomorrow I can dig it out and post some of it.

 

[Ross]

Ross,

Can you quote a Source for that Theory?

Personally, I find it difficult to comprehend.

The notion that NOTHING Happens for 3 days and then 'magically' you get the FULL EFFECT of the Coumadin/Warfarin all-at-once is Scientifically Incomprehensible to me.

To my mind, it is analogous to saying than an aneurism is Safe up to 4.9 cm but at High Risk of Rupture at 5.0 which we KNOW is Not True.

Again, to my mind, it makes more sense that the Warfarin/Coumadin is metabolized SLOWLY and is Finally Fully Metabolized after 3 or 4 days.

Can anyone provide a reference that describes the complete cycle of Warfarin metabolization and subsequent effect on INR? It would be interesting to see a plot of INR vs Time given a constant daily dose of Warfarin.

'AL Capshaw'

(Edited and supplemented version)

Al you think too much like an engineer. Lets put it like this, increasing or doubling a dose is not going to bring your INR up any faster then slow and steady. All it's going to do is perhaps throw you out of range on the high side if that dose was too much.

I can tell you how it went for me in the hospital, but I don't have the paper to show it. 1.1 1.7 2.3 2.7 On my steady dose of 5mg a day at the time. I'm sure it's different for everyone.

Best source I can find so far: http://www.globalrph.com/warfarin.cgi

Initiation: When a rapid effect is required, heparin should be given concurrently for at least 4 days. Loading doses of warfarin are unnecessary in most patients and starting with an average maintenance dose of 5 mg usually results in an INR of 2.0 in 4 to 5 days.

Source
Managing Oral Anticoagulant Therapy
Jack Ansell, Jack Hirsh, James Dalen, Henry Bussey, David Anderson, Leon Poller, Alan Jacobson, Daniel Deykin, and David Matchar
Chest 119: 22S-38S.


Because antithrombotic effect depends on the clearance of prothrombin (which may take up to five days), loading doses of warfarin are of limited value. Because warfarin has a long half-life, increases in the INR may not be noted for 24 to 36 hours after administration of the first dose, and maximum anticoagulant effect may not be achieved for 72 to 96 hours.

http://www.aafp.org/afp/990201ap/635.html