Metformin reaction question

[Isometric]

I had to quit taking metformin a couple of years ago because I was having very painful GI reactions. Over the last couple of months, I've been taking it again and slowly titrating my dose up to 1500mg now (on my way to 2000). Until yesterday, I had not been experiencing the side effects that led me to quit before, but I got hit with one last night. There's no doubt in my mind that it's because of the metformin - it's an unmistakably ugly feeling that I've been through dozens of times before - and the only thing I can think of that might have caused this after so many weeks of no side effects is that yesterday I started taking the 1000mg ER tablets for my morning dose (I've been doing 1000 in the am and 500 pm). Before that, I had been using the 500mg metformin HCL tablets exclusively. Am I grasping at straws here, or is it possible that I'd have a reaction to the ER and not the regular tabs? I went ahead and took the ER again this morning just to see, and depending on how bad it hits tonight (if it does), I'll probably do it again tomorrow to make sure, but I'm a little worried that our HMO isn't going to want to cover twice the amount of pills every month if I can only take the HCL tabs. I know that metformin is widely well-tolerated, but have any of you here experienced something similar, by chance?

Ugh, my gut's already in turmoil - maybe I won't try this tomorrow. :confused:

[EasyType2]

Sorry I can't offer any help, Iso. I've been taking metformin for years and other than some mild nausea the first 3 or 4 weeks, I've never had a problem. Have you discussed this with you doctor/endocriniologist?

[Isometric]

Not yet. Both he and my PCP are aware of my history with the drug, but I won't be able to reach my endo about this latest development until after the weekend.

I forgot to mention that I'd already been on the 1500mg dose for a week before I started taking the ER tab for part of it. I also didn't have to wait until tonight for another round to hit - my stomach's been rumbling since an hour or so after breakfast (and the ER tab), and it's not getting any better. I'll have to see if I've got enough of the 500 tabs to get through tomorrow.

[ladytaz]

Isometric, you can get the 1000mg tablets NOT in ER form! I just take the "regular release" 1000mg tablets, twice a day! ;) Maybe give that a try!

[Isometric]

Thanks for reminding me that I was going to ask if they had those! I'll give the pharmacy a call and see if they can swing that today or tomorrow! Thanks again!

[ladytaz]

You're welcome! I've always gotten those, as they are much cheaper (I don't have insurance). I also haven't had all the GI probs that a lot of people have. I do have an occasional day here and there. But nothing that can't be handled. I've been taking them for 2-1/2 years now.