Thanks for sharing your experience GreenGiant.
You should be just fine.
1) 2.2 is still is the INR safe zone
2) You discovered the mistake by the morning, so you should have only had about a 12 hour delay in your dosage
3) warfarin has a long half-life, which reduces the risk in such an event, although obviously, we still want to take mitigating steps to avoid its occurance.
I've been on warfarin for almost 4 years and did miss one dose in that time. My outcome was similar to yours, seeing a drop in my INR, but still in the safe range.
For a very rough analagy, missing a dose is a bit like playing Russian Roulette. Assuming one is in range at baseline, it is sort of like the gun has a 500 round chamber and one round is placed in it, for missing just one dose. Very low risk that this will lead to an event. On the other hand, if missing dosage becomes a regular occurance, perhaps even multiple times per week, it becomes more like a 6 round revolver or 12 round revolver that we are playing with. Do it enough times and regularly, and it will likely lead to a bad outcome eventually.
And to be clear, I'm not suggesting the odds for the above analogy are accurate, just generally that missing one dose increases our risk, but very minimally. Missing doses often, much more risky.
