FOOD INTERFERES WITH METFORMIN ABSORPTION. How do you take metformin? With food OR an hour before or two hours after a meal?

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Permalink Reply by tmana on October 7, 2009 at 12:33pm

When I was on metformin (extended release), the prescription information said "take with food", and that's what I did, and it worked.

I generally go to Drugs.com to get the professional information on my medications. The page for metformin is here.

Under the section Pharmacokinetics, Drugs.com says:
Absorption and Bioavailability
The absolute bioavailability of a Metformin hydrochloride 500 mg tablet given under fasting conditions is approximately 50% to 60%. Studies using single oral doses of Metformin hydrochloride tablets 500 mg to 1500 mg, and 850 mg to 2550 mg, indicate that there is a lack of dose proportionality with increasing doses, which is due to decreased absorption rather than an alteration in elimination. Food decreases the extent of and slightly delays the absorption of Metformin, as shown by approximately a 40% lower mean peak plasma concentration (Cmax), a 25% lower area under the plasma concentration versus time curve (AUC), and a 35 minute prolongation of time to peak plasma concentration (Tmax) following administration of a single 850 mg tablet of Metformin with food, compared to the same tablet strength administered fasting. The clinical relevance of these decreases is unknown.

In other words, food delays absorption of metformin, but they're not sure if that has any real significance for how well it's working.

Under the section Metformin Dosage and Administration, Drugs.com says:
...Metformin hydrochloride tablets should be given in divided doses with meals...

So, while it sounds contradictory, it would appear that you have the correct information.

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Permalink Reply by Lucile K. on October 8, 2009 at 6:57am

Thanks tmana for your reply and the link to info about prescription medications. I bookmarked Drugs.com for future reference. I'll continue to take metformin as directed "With food."

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Permalink Reply by Ellie on October 8, 2009 at 7:02am

I take 3 doses a day, none of them with a meal, unless coincidentally (I assumed that instruction was in case of stomach upset, which I don't have). I take one at mid-day/early afternoon/when I think of it, one at bedtime, and one between 3-4AM when I get up to go to the bathroom, which helps me with my dawn phenomenon. I've experimented over the years and this works best for me, and my doctor trusts me to take things when they work best for me. But I have never taken them with food.

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Permalink Reply by Lucile K. on October 11, 2009 at 7:50am

Thanks for your reply Ellie, Seems to me that taking metformin at bedtime (I strive for 10:30PM)--or between 3-4AM as you do--would have a better effect on the dawn phenomenon--instead of at dinner time as I do. I'm suppose to submit my bs numbers (fasting & before dinner) to endo in a month. I'd like to experiment too. But probably will wait one month although this morning's fasting bs was 122.

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Permalink Reply by Cathy Jacobson on October 8, 2009 at 7:56am

I take it twice a day at 1000 mg a time. I have taken it on an empty stomach ( usually don't have trouble with meds taken this way) but found that I didn't feel just perky at the time....so started taking it either right before eating or right after. My doc and pharmacist concurred that if it keeps my bs's down and doesn't upset my stomach, then this would be the way to take it.

I never start a new med with out getting the med sheet. Wally World's pharmacy offers them as a matter of practice with each refill that you get....so I've got dozens of them for every med I take...and it includes what meds I am on, what ones I have taken in the last three years and if there could be or is a problem of taking them together. Just a blatant plug. You can call the pharmacy where you get your meds and ask them to send it to you, if you won't be going in sooner than you want to know.

Just a thought.

As you know, each of us is very different in what works and what doesn't work, so a real discussion about this would have to be with your doc, I would think....

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Permalink Reply by Shilpa on October 8, 2009 at 5:30pm

This article you found is really interesting . . . .I take 1000mg of metformin extended release twice a day. At night, I would take it at bedtime (a few hours after eating) but recently started taking it with dinner. Taking the metformin ER with dinner, I've noticed my numbers are a bit higher (about 20mg/dL) even though my diet hasn't changed and neither has my weight or any of the other factors . . . .Maybe I'll try taking it later again and see if it drops.

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Permalink Reply by Lucile K. on October 11, 2009 at 8:03am

Please let me know your results Shilpa if you do start taking your metformin later (at bedtime) again. I'd like to experiment too but think I should wait a month before deviating from my endo's directions. Thanks for your reply.

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Permalink Reply by Lucile K. on October 11, 2009 at 7:56am

Thanks for your reply Cathy, I agree that each of us is very different in what works and what doesn't. Also, as recommended, I got a copy of the full med sheet from my pharmacy on metformin. I like getting input from the Tudiabetes community--that is, been there, done that, type of input so I'm not totally ignornant about things I need to talk to my doctor about. Plus, I find that the turnaround time in getting a response back is often faster on this website than from my doctor's office.

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