The Anonymous Widower

Is There An Interaction Between Bisacodyl And Warfarin Or INR Self-Testing?

I am on long term Warfarin and since 2012, I have self-tested my INR using a Roche Coaguchek device.

I have had no problems and for perhaps the last five years, I have been on a regular daily dose of four mg.

I should say, I’m a trained Control Engineer and if you can keep any inputs, like drug dose, constant, you should get a stable system.

Recently, I have been suffering from severe constipation and my GP has prescribed bisacodyl. I have taken it perhaps five time before bed and it works well

On Friday, I was feeling constipated, so I took one of the bisacodyl tablets before bed.

On Saturday, I tested my INR using a strip from a newly-arrived box direct from Roche  and found it was a rather extraordinary 5.2.

I had never seen a result higher than 3.2 before and put it down to one of the following reasons.

1. The box of new strips was faulty. I have had dodgy ones before in the past, but not recently.
2. There is an interaction between bisocodyl and warfarin. There are no reports on respected sites on the Internet.
3. There is an interaction between bisocodyl and the Coaguchek testing process. There are no reports on respected sites on the Internet.
4. I inadvertently took the wrong dose of warfarin.

I took a dose of two mg. yesterday and this morning I tested myself again twice.

• With a strip from the new box, found a reading of 5.3.
• With a strip from an old box, I found a reading of 5.

I shall test myself daily until I sort this out.

February 16, 2020 - Posted by AnonW | Health | CoaguChek, INR, Warfarin