Posting this under the heading it deserves: Alcohol: what is documented and what is folklore Everything below is what sits behind that.
Alcohol, and specifically the version of it that the documentation does not cover. The maintained page handles the general case well and stops exactly where my question starts.
Setting out the gap in case it is a gap in the page rather than a gap in what is known.
The arithmetic in the opening post is right; the assumption feeding it is the part to check.
Alcohol is not contraindicated in the labelling and it does irritate a stomach that is already emptying slowly. There is no published interaction study, and the conservative reading is the obvious one.
That is the shape of it. The detail is where I would expect to be corrected.
Post #2 put the caveat in the right place and I want to underline it.
A pharmacist can answer most questions in this subcategory in a few minutes with access to a proper interaction database, and that access is the thing a forum does not have.
If the premise is wrong, everything after it is decoration.
Narrowing post #4, because the general version has more than one answer.
A note on how alcohol gets discussed rather than on alcohol itself: the confident posts get the replies and the careful ones get ignored, and the careful ones have been right more often.
Anything that also slows gut motility compounds the same mechanism. That is a plausibility argument rather than a documented interaction, and it should be labelled as one.
Post #8 is right about the mechanism and I think understates the practical bit.
Adding what did not work for me on alcohol, since the failures never get written up and they are half the useful information.
SGLT2 inhibitors: frequently co-administered and relevant to renal and cardiovascular discussion, not to interactions. There is no pharmacokinetic interaction of concern.
Everything in post #9 holds. The case it does not cover is the one I have.
Speaking only to alcohol 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 #9, because the general version has more than one answer.
The useful distinction on alcohol is between what was measured and what was inferred from it. Both end up in the same sentence and only one of them has error bars.
Alcohol: no absolute contraindication but it raises gastrointestinal irritation risk and this drug class already does that. The conservative position during titration is to limit it.
The answer changed when I changed how I was measuring, which was informative.
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.
I read post #13 twice before replying, because I had assumed the opposite.
Two claims get bundled together under alcohol and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.
Almost every disagreement in threads like this one dissolves once you say which of the two you are making.
On alcohol, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.
If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.
This is the answer, and the reason it is the answer is the more useful part.
Taking post #16 at face value and following it one step further.
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.
Two things can be true about alcohol at once: the mechanism is plausible and the evidence for the size of the effect is thin. Most of the argument here is people defending the first against attacks on the second.
Confirming post #18 from a second method, which matters more than confirming it from a second person.
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.
Alcohol is not contraindicated in the labelling and it does irritate a stomach that is already emptying slowly. There is no published interaction study, and the conservative reading is the obvious one.
The interesting part of this is the exception, and I do not understand the exception.
The reason alcohol is hard to answer is that the obvious measurement and the relevant quantity are not the same thing, and substituting one for the other is silent.
Saving this. It is the version I will quote when the question comes round again.
Alcohol has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
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.
On reflection I would soften that slightly.
The claim about alcohol upthread is stronger than its source supports. I have read the source. The source says "associated with" and the post says "causes".
Post #25 describes the usual case. This is about the unusual one.
My understanding of alcohol is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating 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.
It is worth stating the boring hypothesis before the interesting one.
Post #29 put the caveat in the right place and I want to underline it.
Something worth flagging about alcohol: the strongest-sounding claims in this thread are the ones with no source attached, which is the usual pattern and not a coincidence.