On the subject in the title: Second pass at: Metformin co-administration and additive GI effects Working notes rather than a conclusion.
Posting a small dataset on Metformin co-administration. It is mine, it is uncontrolled, and the method is stated so it can be discounted appropriately.
What I would like is not agreement but a second dataset collected by someone with no stake in mine. If one exists I would rather read it than argue for this one.
A supplement is a drug for interaction purposes, and the fact that it is sold without a prescription tells you nothing about whether it interacts. The paperwork is usually worse rather than better.
Adding it in case it saves somebody the afternoon it cost me.
On post #4 — agreed on the reasoning, with one qualification.
Where a published interaction study exists it usually reports an area-under-curve ratio, and that number is far more informative than a yes-or-no answer.
Correct me on the arithmetic if it is wrong; I would rather know.
Metformin: commonly co-administered and relevant to gastrointestinal tolerability. Gastrointestinal side effects can overlap and additive. Taking them separately or adjusting one if tolerability is poor are reasonable approaches.
The claim is narrower than it sounds, and deliberately so.
An update on my earlier Metformin co-administration post: the pattern held for another six weeks and then stopped, which I did not predict and cannot explain.
Anticoagulant questions come up regularly and are the clearest case for professional advice rather than discussion, because the consequence of being wrong is not gradual.
That matches what I was told, which is not the same as knowing it.
A request rather than an answer: could whoever has the primary source for Metformin co-administration post it? I have seen the claim three times this month and each version had lost a qualifier.
Everything in post #11 holds. The case it does not cover is the one I have.
Speaking only to Metformin co-administration as I have actually seen it, rather than as it is usually described: the effect is real, it is smaller than the thread suggests, and the variance between people is larger than the effect.
Narrowing post #11, because the general version has more than one answer.
The most defensible general position in this subcategory: identify the plausible mechanism, check whether it has been studied, and where it has not, say that rather than filling the gap.
What would change my mind on Metformin co-administration is a second dataset collected by someone with no stake in the first. Until then I hold it loosely and I would rather say so than pretend to more.
Taking post #15 at face value and following it one step further.
I changed my mind about Metformin co-administration after someone here asked me for the source and I could not produce one. That is worth saying out loud because it is the ordinary way it happens.
Adding a note of thanks rather than an opinion. I did not know most of that.
Worth separating two things that post #15 runs together.
I would rather this thread reach "we do not know" about Metformin co-administration than reach a confident answer that nobody can support when asked.
This follows post #19 rather than contradicting it.
Where a published interaction study exists it usually reports an area-under-curve ratio, and that number is far more informative than a yes-or-no answer.
The arithmetic in post #20 is right; the assumption feeding it is the part to check.
Food interactions: most interactions are absorption interactions. Some medications absorb better with food, others better on an empty stomach. With an incretin agonist that already slows gastric emptying, food effects interact with the drug effect as well.
That is all I can say without guessing.
A supplement is a drug for interaction purposes, and the fact that it is sold without a prescription tells you nothing about whether it interacts. The paperwork is usually worse rather than better.
Nothing above should be read as advice about what anyone else should do.
The most defensible general position in this subcategory: identify the plausible mechanism, check whether it has been studied, and where it has not, say that rather than filling the gap.
It is the kind of thing that is obvious once and never again.
Adding the measurement that post #24 says would settle it.
For anyone finding this later: the short answer on Metformin co-administration is that it depends on one thing, and the rest of the thread is people identifying which thing.
Post #26 describes the usual case. This is about the unusual one.
Anticoagulant questions come up regularly and are the clearest case for professional advice rather than discussion, because the consequence of being wrong is not gradual.
The step people skip is the one I have spelled out.
Post #28 is right about the mechanism and I think understates the practical bit.
Where I have landed on Metformin co-administration, having got it wrong once in public: the direction is clear, the magnitude is not, and anyone quoting a precise magnitude has borrowed it from somewhere that did not measure it.
No notes. Posting so the count is not one.