It’s been an interesting week with Metformin. I’m actually still trying to figure out a lot.
After dropping my basal dose (to 23 units), I stopped having the drops, but I started trending upward all the time and having bigger peaks after meals. I considered stopping metformin altogether because it was clearly not helping with the problem. I bumped my dose back up a unit (24 now) so I had sufficient basal.
Then I acccidentally forgot my morning metformin dose!! I had several important meetings that day and didn’t want to make the trip home. I ended up researching a bit online, and I found out that metform XR peaks about 6 hours after ingestion. By 12 hours, there’s only a low level amount left (if I’m understanding the graph below correctly). If you’re fasting, it peaks and declines even sooner.
I decided to switch my dose to the evening (at dinner) which worked out conveniently because I’d forgotten my dose that day anyway. The next couple days were pretty chaotic bg wise. I think missing a metformin dose is a really big deal. Maybe if I’d been on Levemir I could’ve simply increased my Levemir dose for a day or two, but that doesn’t work as well with Tresiba. I just rode it out and things started to normalize about 36 hours later.
If I’m going to stay on Metformin though, I cannot miss a dose!
Now I’ve only had a couple nights with the evening Metformin dose, but I am seeing an impact. It’s really helping. I’ve been able to keep the same basal dose (24 units). I’m not seeing drops during the day while walking at all (my current theory is that it’s because the Metformin has mostly worn off by then). I went for a 45 minute walk yesterday, and I just had the normal slight decline I used to have.
These are my takeaways at this point:
- Metformin should be taken so that it is peaking (or at least pretty active) during the time frame you suspect you have the most insulin resistance.
- An overall basal insulin dose decrease may still be necessary. I’m suspecting that I’ll be able to maintain my 1 unit/day decrease.
What I’m still learning and trying to figure out:
- How Humalog and Afrezza are affected by Metformin (for me). I don’t have solid conclusions on this… just a bunch of theories. Afrezza is not acting the same for me though. I plan to research and test this more.
- I think Metformin (taken in the evening) might make me more sensitive to alcohol? I know that there’s a risk of lactic acidosis while taking metformin and drinking. After trying my best to research online, I decided that drinking 1-2 glasses of wine was fine as long as I hydrated well. I don’t think I’m experiencing lactic acidosis (it seemed that this was relatively rare). I didn’t notice any difference when I took my dose in the morning, but I suppose that makes sense because there would’ve been less metformin in my system by the evening. Anyway, just something I’m watching.
- I have experienced some slowed digestion (constipation) over the last couple of days (since I switched my dose to evening). Hopefully that either is unrelated or doesn’t stick around.