Self dosing question

[NorthVanJosh]

Hi all,

My INR during my hopsital stay a week ago was all within the 2-3 target range. I have been on 5mg per day. After being discharged my readings went from 2.9 > 2.4 > 1.7 and just today at 1.6. My doctor advised me after the 1.7 reading that if the next reading was below 2 again then he would up my dose by 20%.

Unfortunately he is on vacation until Tuesday and I am unable to get in contact with the heart unit that did my surgery too.

Wondering if I am ok to up my dose to 6mg a day till Tuesday (a 20% increase like he stated). Or am I missing something? Sorry I am new to the whole INR life!

 

[Standardvelocity]

I would increase to 6mg, my dose had to be increased several times after release from hospital. In my opinion higher is more desirable than lower out of range.

 

[pellicle]

Wondering if I am ok to up my dose to 6mg a day till Tuesday (a 20% increase like he stated). Or am I missing something? Sorry I am new to the whole INR life!

yep .. I'd also increase dose. Nobody will smack your wrists.

The actual reason you are on warfarin is to attain a specific INR not a specific dose.

Its pretty well documented that after surgery your recovery will see your "sensitivity to warfarin" decrease (meaning more dose). Surprised me, but I worked it out.

https://pubmed.ncbi.nlm.nih.gov/19336266/

Conclusions: Patients steadily become less sensitive to warfarin during the first months after heart valve surgery. This leads to subtherapeutic anticoagulation. A dosing algorithm that takes increasing requirements into account is proposed. This algorithm will need to be validated prospectively.​

Best Wishes

 

[dick0236]

I agree with Standardlocity to increase to 6mg and followup with your doc.

 

[NorthVanJosh]

Thanks guys. I increased it to 6mg today and will take that till Tuesday when I can talk to the doc. Will also get my blood retested again on Saturday and hopefully see a increase.

 

[tommyboy14]

For info, i left hospital on 4mg, now my maintenance dose is 9.5mg.

 

[Chuck C]

Studies have shown that it is often necessary to increase warfarin in order to stay in range, for several months following the initiation of warfarin. I have personally found this to be true, as did @tommyboy14. I was at about 3.5mg/day upon release, which kept me at my target INR of 3. About 6 months after surgery my INR target was lowered to 2.5. Even though my INR target was lower, by then I needed to be at about 6.5mg/day to stay in range. And that is about where it has stayed since then.

 

[pellicle]

not specifically to chuck, but more generally

Studies have shown that it is often necessary to increase warfarin in order to stay in range, for several months following the initiation of warfarin

a for instance
https://pubmed.ncbi.nlm.nih.gov/19336266/

Decreasing warfarin sensitivity during the first three months after heart valve surgery: implications for dosing​

Results: A steady increase in warfarin requirements was seen over the three months in patients with mechanical valves, bioprosthetic valves or valve repairs. The mean dose of warfarin increased by 26% while the mean INR decreased from 2.5 to 2.1. In contrast, both the mean dose of warfarin and the INR were stable in controls. TTR in patients after valve surgery was 48.5%, with 40.8% of time spent at an INR below 2.0. A dosing algorithm was modeled from the data in this patient group.​

 

[NorthVanJosh]

Well INR is still out of range, tested at 1.8 today. And that was with my increasing my dosage to 6mg for the past few days. Bumped todays up to 7mg and will wait to see what the doctor says. Kinda getting a bit worried as I've been out of range for 8 days now, but I do have an On-x valve so hopefully its not too big of a deal. Here's hoping I'm in range when I retest on Thursday!

 

[3mm]

INR is still out of range, tested at 1.8 today. ... Kinda getting a bit worried as I've been out of range for 8 days now, but I do have an On-x valve so hopefully its not too big of a deal.

NorthVanJosh - You'll be fine!

Last January I had pneumonia, which caused my INR to drop to 1.5 - 1.8 range for 3 weeks in spite of increased Warfarin doses. Like you, I have an On-X aortic valve, so I was concerned, but I stayed calm, maintained control of my life, took INR measurements twice a week, and slowly increased my Warfarin dose until we got me back in range. I am very glad that I have used 2.5 as my INR target, and always considered the 1.5 - 2.0 range to be a safety margin.

 

[carolinemc]

Hi all,

My INR during my hopsital stay a week ago was all within the 2-3 target range. I have been on 5mg per day. After being discharged my readings went from 2.9 > 2.4 > 1.7 and just today at 1.6. My doctor advised me after the 1.7 reading that if the next reading was below 2 again then he would up my dose by 20%.

Unfortunately he is on vacation until Tuesday and I am unable to get in contact with the heart unit that did my surgery too.

Wondering if I am ok to up my dose to 6mg a day till Tuesday (a 20% increase like he stated). Or am I missing something? Sorry I am new to the whole INR life!

Never just self dose without knowing your INR Number. Just do the dose as you have been and wait till your next lab Protime. They know what they are doing.