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Peggy_TX

Metformin vs Metformin ER/XR - dosage

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I asked my doc about switching from Metformin to Metformin ER and was totally confused by his answer.

 

I've been taking Metformin 850 2x/day

 

He insists that the Metformin 750 XR ONCE PER DAY is the closest equivalent dosage

 

Basically he's saying that the XR is TWICE as strong as the regular -- and NOT that it provides the same amount in a quicker release

 

He gave me a script for 500XR 2x/day, but I'm worried that's a HUGE decrease in Metformin from 850 regular 2x/day

The way I interpret this, I'll be getting 1000 units of metformin/day instead of 1700 -- he says I'll be INCREASING the level of metformin in my bloodstream at any given time............

 

Can anyone point me to anything that I can give him to refute this?

 

Or tell me he's right and I shouldn't worry?

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All I know is that maximum dose Met ER is 2,000 mg. Maximum dose regular Met is 2550. I've heard that the maximum for regular is because no additional benefit is achieved with a higher dose, not that a higher dose is harmful. You would need to verify that.

 

I also have my own personal experience of having previously been on 2,000 mg Met ER for 6 months. I don't know where I got this idea (Bernstein? Not sure) that regular Met is more effective than Met ER. I asked my endo to switch. He shrugged his shoulders like, why not, and wrote the script but I don't think he was particularly convinced there would be much of a difference. At the time I was on 38 units of Lantus. I was quickly able to lower my Lantus to 28 units. I eventually got to 21 units over the next few months but I also lost some more weight. Lantus is back up to 30 units now but I'm also up 8 pounds as well. Anyway, I most definitely had an initial substantial reduction in my Lantus when switching to regular Met.

 

Why do you want to go on ER?

 

Basically, Peggy, keep an eye on your numbers. They will tell the story.

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I have the occasional "metformin moments" of needing to get to a bathroom quite quickly. Those don't happen that often, but I could certainly live without them! (1/month???)

The more concerning issue is that I've had chronic "loose stools" since being on Met. Not diarrhea, but not what they're supposed to be.

I had a GI doc once tell me that stools should "retain the form of their container" I think that's a nicely descriptive way to explain what's normal and what's out of normal.... and I've been "out of normal" for a while. Could be any number of other explanations, but if I switch and it improves, then I know the cause.

 

So when you went from ER to regular and back, you retained the same basic total dosage? 2000ER to 2000regular? And the 2000 regular was MORE effective, not half as effective?

This is consistent with what I'm thinking, and backwards of how my doc is understanding it.

I think going from regular 850, 2x/day to 500ER 2/day is going to DROP my dosage and screw up my blood sugar.............

 

Anyone have anything else to back up how the daily totals should line up?

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Peggy, I am not an expert. But, my understanding is that 2000 is the max dose for ER and

 

2550 is max dose for regular. Therefore it would make sense that you would take a lower dose

when switching to the ER. The other thing to keep in mind is that ER means that the medicine

is being released a little bit at a time so that the met is in your system consistently. Theoretically

anyway. So, I think your doctor is probably correct. If the ER doesn't work you still have some

room to increase the dosage.

 

Good luck with new medicine regime.

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I take the regular-2550. I asked my doctor if I should switch. He told me the 2000 mg of the ER was not as strong and I shouldn't switch because my bgs would go up. So I stuck withnthe regular and just played around with the timing.

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Get your pharmacist's opinion on this notion that ER is stronger.

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Guess I'll give it a month and see what happens ("side effects" vs blood sugar levels)

He's happy enough to switch me back if I call and ask.

 

I get that the ER "isn't as strong" -- but I'm still confused as to whether that's comparing 1 ER to 2 non-ER as my doc seem to think... I still kinda think he has it wrong, and has WAY "underprescribed" for me!

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I take the max dose of er version in a split dose. 1/2 in am 1/2 in pm. I do see an immediate (or quick) response when I take it, but its nice not having the constant fear of *explosion* that I was prone to with the regular. I do still have occasional bouts, but not like on regular.My sugars typically run between 95-115 on a low carb diet. I don't count calories per se, but do keep carbs below 50 a day most days. I also take Januvia which seems to have helped with my morning numbers a little bit. I show a big response in my numbers to more that 10-12 carbs at a time, so spread them out. My breakfast doesn't include carbs...just eggs and meat if I'm hungrier than usual will include some veggies leftover from dinner. Its what has worked for me. I DO like the ER version so I'm not so tied to the mealtime taking of pills.

v.

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I never take my regular metformin at meals. It works a lot better that way for me and causes less stomach upset than with food.

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Well... I called my doc back and fussed at them.

They finally got bored of arguing with me, and changed the script from 500ERx2 to 750ERx2. With a huge lecture about testing and making sure I don't get a hypo, etc etc

Whatever. It's actually a level that I think is "in the ballpark" of what I've been taking (AND I think it's less -- not more!)

Starting them this morning -- we'll see what effect it has on my digestion and blood sugar levels

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I've really never experienced a hypo with the metformin. I had lots of false hypos during my initial bs lowering, but have not had anything under 70 or so. My liver kicks in before I get there. V.

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As stated above, I think my doctor is being bizarre.

He's completely convinced that 750ERx2 is nearly DOUBLE the dosage of Met I've been taking (850non-ERx2)

While *I* am convinced that the new prescription is LESS than what I've been on....

(and I seriously doubt a hypo from Met, even if he raised the amount to 1000ERx2!!!)

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Met cannot directly cause a Hypo; that's not how it works.

 

however, since it reduces insulin resistance AND reduces the capability of the liver to dump sugar when you DO go low, Met will cause whatever lows you do have to last longer (body responds more slowly to the low)

 

Your doc sounds like a quack.

 

500 ER = 500 Regular.

 

However, 2000 ER = 2250 Regular

 

This is due to bioavailability from the delayed release of the ER when compared to the rapid release of the Regular. Take too much Regular at any one time and a percentage of it will end up being excreted without ever being absorbed or taking effect in your body **.

 

** ... actually, the unabsorbed "extra" Met that does not have a biochemical effect on your body is generally responsible for the worst of the "Metformin Moments" which is why many people who cannot take regular Met are able to take ER.

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Seriously, how often do you read about Metformin caused hypos around here? :confused:

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Somehow I may not be expressing myself ...

My reason for starting this thread was my doc insisting that ER is 2x stronger than non-ER.. apparently because it lasts twice as long.

Which was totally bizarre, and I was just checking to make sure I wasn't losing my mind.

My doc is NOT a diabetes expert. His specialty is sports medicine. And I like him, 'cause he mostly does what I tell him and doesn't push drugs.

I mentioned the "hypo warning" he gave me when he upped the script to what I wanted, only because I thought it was funny. And helped highlight how stuck he was on this belief about the dosages between ER and non-ER

I do NOT worry that this new dosage will give me a hypo.

I had really wanted someone to initially address my question about the 2x strength... but no one did, so I just called the doc back and insisted anyway.

That's all.

And now I'm

1) hoping it might help with some of my GI issues (which were NOT that bad to begin with, so I'm willing to switch back if the improvement isn't there)

and

2) wondering if the 750ERx2 will give me better or worse sugar control than the 850non-ERx2 has

Which is something only time will tell I guess

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I used to take 1700 mg of metformin but my fastings bgs were still higher thsn 130. So I asked my internist who does specialize in diabetes to up it to 2550. I got the same lecture about hypos. At that time I rarely went below 130 and my liver would always dump glucose as I approached 130. It took me several visits to convince him to up my dose. Within 2-3 weeks I was seeing 100 or lower and no HYPOS.

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Somehow I may not be expressing myself ...

My reason for starting this thread was my doc insisting that ER is 2x stronger than non-ER.. apparently because it lasts twice as long.

Which was totally bizarre, and I was just checking to make sure I wasn't losing my mind.

My doc is NOT a diabetes expert. His specialty is sports medicine. And I like him, 'cause he mostly does what I tell him and doesn't push drugs.

I mentioned the "hypo warning" he gave me when he upped the script to what I wanted, only because I thought it was funny. And helped highlight how stuck he was on this belief about the dosages between ER and non-ER

I do NOT worry that this new dosage will give me a hypo.

I had really wanted someone to initially address my question about the 2x strength... but no one did, so I just called the doc back and insisted anyway.

That's all.

And now I'm

1) hoping it might help with some of my GI issues (which were NOT that bad to begin with, so I'm willing to switch back if the improvement isn't there)

and

2) wondering if the 750ERx2 will give me better or worse sugar control than the 850non-ERx2 has

Which is something only time will tell I guess

 

I've understood you, Peggy. :) I just can't help you out with your doc's belief that XR is twice as potent as regular. It makes no sense to me. Why would max dose XR be 2,000 mg per day and max dose regular be 2,550 per day if XR was twice as potent? I've never heard that XR is twice as strong. I'm guessing that no one who has read the thread has heard that either or they would have responded. Have you asked your pharmacist's opinion on that claim?

 

About Metformin causing hypos, my post above was in dismay that your doc and/or his staff believe that Metformin can/may cause hypos. I didn't think that you were concerned about that or of that belief yourself. :)

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For me, Metformin is like taking a placebo. I am taking Janumet + Glipozide. Years ago I was taking Metformin ER and was getting vertigo-- dizzy, falling out. Because I wasn't eating before I took the medication.

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