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Delayed gastric emptying and oral medication absorption: which drugs matter posts 31–60

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This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.

r.petrovTL230 Mar 2025#31

a.weiss, post #11: Summarising the delayed gastric emptying and oral thread so far, since it is long and the answer is buried: the first reply has the method, the fourth has the correction to it, and the rest is people agreeing at length. Go to post

Where I part company with post #29, and it is a narrow parting.

The bit of delayed gastric emptying and oral that nobody enjoys is that the answer changes depending on what you are trying to decide with it. Say what the decision is and the thread will converge.

19 likes in reply to #11 16mo

ppm_errorTL3Analytical chemist31 Mar 2025#32

Second-hand on delayed gastric emptying and oral, so weight it accordingly — someone whose method I trust told me this and I have not verified it myself.

8 likes 16mo

b.vanheckeTL21 Apr 2025#33

Thyroid medications: semaglutide is associated with a slowing of gastric emptying, which might affect thyroid medication absorption if they are taken very close together. Separating them by a few hours is the conservative approach.

2 likes 16mo

chromatogramTL4Analytical chemist2 Apr 2025 · edited#34

r.frisk, post #23: Two questions I would want answered before drawing anything from the delayed gastric emptying and oral data above: how were the cases selected, and what happened to the ones that dropped out. Go to post

Adding the measurement that post #33 says would settle it.

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.

I am not the right person to answer the follow-up to this.

0 likes in reply to #23 16mo

n.vukovicTL23 Apr 2025#35

Collapsed as off-topic by two members at trust level 3 or above

Post #33 put the caveat in the right place and I want to underline it.

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.

That is the version I use. It may not be the version that is correct.

appeals_deskTL3Regular4 Apr 2025#36

Building on post #33 rather than restating it.

The arithmetic on delayed gastric emptying and oral is the easy part and it is where the errors are, which is an uncomfortable combination. Show your working and someone will catch it.

12 likes 16mo

y.rahimiTL25 Apr 2025#37

Adding a note of thanks rather than an opinion. I did not know most of that.

4 likes 16mo

preregisteredTL3Research methods6 Apr 2025#38

l.aguirre, post #22: Post #18 and I disagree about the size of the effect, not about the direction. 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. The variance between people here is larger than the effect being discussed. Go to post

Oral contraceptive absorption has been studied specifically for some compounds in this class and the findings are compound-specific. Generalising from one to another is not supported.

0 likes in reply to #22 16mo

a.teixeiraTL27 Apr 2025#39

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.

8 likes 16mo

resistance_firstTL2Regular8 Apr 2025#40

Post #38 is right about the mechanism and I think understates the practical bit.

The claim about delayed gastric emptying and oral upthread is stronger than its source supports. I have read the source. The source says "associated with" and the post says "causes".

2 likes 16mo

n.lehtinenTL28 Apr 2025 · edited#41

taper_file, post #10: That matches what I have seen, for whatever a single anecdote is worth. Go to post

Confirming post #38 from a second method, which matters more than confirming it from a second person.

Answering the delayed gastric emptying and oral question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.

25 likes in reply to #10 16mo

a.ibarraTL29 Apr 2025#42

MSaarinen, post #19: 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. Go to post

I had written a reply contradicting post #40 and deleted it. Here is what survived.

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.

Two sources, same conclusion, and I could not rule out that one copied the other.

0 likes in reply to #19 16mo

n.rahimiTL210 Apr 2025#43

The practical advice most consistently given by pharmacists here is to keep the timing of other oral medication consistent rather than to change it, because consistency is what makes a problem visible.

Happy to be corrected if someone holds better data than mine.

3 likes 16mo

l.dziedzicTL211 Apr 2025#44

Timing separation is the standard mitigation where absorption rate is the concern, and the interval that matters depends on the other drug rather than on this one.

11 likes 16mo

d.oyelaranTL3Pharmacist12 Apr 2025#45

Post #42 is right about the mechanism and I think understates the practical bit.

Oral medications with a narrow therapeutic index are the ones where that matters most. The interaction is about rate and timing rather than about the total absorbed, in most published cases.

This is the sort of thing the wiki should carry and currently does not.

18 likes 16mo

h.vargaTL213 Apr 2025#46

Collapsed as off-topic by two members at trust level 3 or above

Separation timing versus clinically important interaction: a separation timing inconvenience (taking one medication 2 hours before or after another) is not the same as a clinically important interaction. Both can reduce absorption of one or the other, but only true interactions require active management.

Reading it back, the second half matters more than the first.

KLindqvistTL4 Moderator14 Apr 2025#47

That is a fair summary of where the discussion has got to.

1 like 15mo

c.tullochTL215 Apr 2025#48

Marking my uncertainty on delayed gastric emptying and oral explicitly. I am confident about the direction, much less confident about the size, and not confident at all that it generalises past the case in the first post.

7 likes 15mo

physio_marchettiTL2Physiotherapist15 Apr 2025#49

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.

Posted with less confidence than the sentence structure implies.

12 likes 15mo

j.iyerTL216 Apr 2025#50

a.almeida, post #12: 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 number is defensible. The precision I gave it is not. Go to post

Vitamins: most vitamins have no significant interaction. Fat-soluble vitamins (A, D, E, K) might be affected by the slowing of fat absorption during weight loss, but that is a nutritional consequence rather than an interaction.

26 likes in reply to #12 15mo

revision_historyTL3Wiki editor17 Apr 2025#51

I read post #48 twice before replying, because I had assumed the opposite.

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.

I would treat that as a working assumption and revisit it.

0 likes 15mo

a.adeyemiTL218 Apr 2025#52

Post #51 answers the question as asked. The question underneath it is different.

Delayed gastric emptying is the mechanism behind most of the plausible interactions in this class: anything whose absorption depends on how quickly the stomach empties can behave differently.

22 likes 15mo

week_threeTL1Member19 Apr 2025 · edited#53

Adding a null result on delayed gastric emptying and oral. I looked, carefully, and found nothing, and null results deserve posting precisely because they never are.

6 likes 15mo

j.ivaturiTL220 Apr 2025#54

KLindqvist, post #18: Post #15 answers the question as asked. The question underneath it is different. Practical answer on delayed gastric emptying and oral, since the theoretical one is upthread: do the simplest check first, write down the result, and only then decide whether the complicated explanation is needed. It usually is not. Go to post

Delayed gastric emptying and oral would be much easier to settle if anyone reported the denominator. Almost nobody reports the denominator.

1 like in reply to #18 15mo

h.oyelowoTL2Regular20 Apr 2025 · edited#55

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.

A weak preference rather than a position.

0 likes 15mo

ro.zielinskiTL221 Apr 2025#56

Narrowing post #55, 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.

Noting that I have skin in this question and have tried to discount for it.

30 likes 15mo

microgramsTL2Regular22 Apr 2025#57

Good question, well framed, and I would like to see it answered properly.

10 likes 15mo

m.radichTL223 Apr 2025#58

k.salinas, post #13: SGLT2 inhibitors: frequently co-administered and relevant to renal and cardiovascular discussion, not to interactions. There is no pharmacokinetic interaction of concern. The part I am sure of is shorter than the part I have written. Go to post

A note on scope: what I am saying about delayed gastric emptying and oral applies to the case in the first post and I would not extend it further without checking.

3 likes in reply to #13 15mo

r.marsdenTL3Regular24 Apr 2025#59

What would change my mind on delayed gastric emptying and oral 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.

23 likes 15mo

f.fontaineTL225 Apr 2025#60

SGLT2 inhibitors: frequently co-administered and relevant to renal and cardiovascular discussion, not to interactions. There is no pharmacokinetic interaction of concern.

If anyone has run this properly I would rather read that than my own guess.

11 likes 15mo