Renal impairment: what the labelling says about dose — setting out what I have, and where I think it stops being reliable.
Renal impairment — I have the observation and I do not trust my interpretation of it, so I am posting the observation and holding the interpretation back.
Numbers, method and the conditions under which they were collected are below. Interpret them however they warrant.
Hepatic impairment: less is known about dosing in significant liver disease than in kidney disease. Extreme caution applies because the liver metabolises a large fraction of many medications.
It is the sort of thing that seems obvious in retrospect and was not at the time.
Hypoglycemia risk: in people already on insulin or sulfonylureas, adding a GLP-1 agonist requires insulin dose reduction and close monitoring for hypoglycemia. This is manageable with attention.
The evidence for this is thinner than the way I have phrased it suggests.
On post #3 — agreed on the reasoning, with one qualification.
Dedicated trials in under-studied populations are the only real remedy and several are ongoing, which is worth saying rather than speculating.
On reflection I would soften that slightly.
Where a labelling document addresses a population explicitly, that text is the single most useful thing to quote in a thread.
A modest claim, modestly supported.
Where the Renal impairment discussion usually stalls is that nobody wants to say "I do not know" and everyone is willing to say "it varies". Those are the same sentence with different clothes on.
One caution on Renal impairment: everything above assumes the underlying documentation is what it claims to be. That assumption is doing real work and is rarely stated.
Extrapolating a point estimate to somebody well outside the enrolled range should be described as an extrapolation every time it is done.
It is the kind of thing that is obvious once and never again.
Post #10 describes the usual case. This is about the unusual one.
The version of Renal impairment that I was taught turned out to be a teaching simplification. Useful, and not true in the way I had assumed it was.
What I want from this Renal impairment thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.
Body weight at the extremes of the studied range affects exposure and the trials rarely reported enough to say by how much.
The reasoning is more useful than the number, which is why I have shown it.
Answering the question post #14 raises rather than the one it answers.
Pregnancy and breastfeeding are the clearest cases where the answer is that the trials excluded them and the labelling reflects that exclusion.
Two questions I would want answered before drawing anything from the Renal impairment data above: how were the cases selected, and what happened to the ones that dropped out.
Helpful, and easy to find again, which is half of what a good reply is.
Hepatic impairment: less is known about dosing in significant liver disease than in kidney disease. Extreme caution applies because the liver metabolises a large fraction of many medications.
One case, stated as one case.
Coming back to post #23, because the follow-up matters more than the original answer.
Renal and hepatic impairment studies are usually small dedicated pharmacokinetic studies rather than outcome trials, and they answer exposure questions only.
Anyone with a larger sample, please post it.
I would put moderate confidence on the mainstream reading of Renal impairment and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.
This follows post #27 rather than contradicting it.
Nothing in this subcategory is medical advice and the questions asked here are precisely the ones that need an individual assessment.
Answering the question post #27 raises rather than the one it answers.
Genetic and ancestry-related differences in response are asked about regularly and the published evidence is thin enough that the honest answer is short.
The arithmetic in post #27 is right; the assumption feeding it is the part to check.
Worth separating Renal impairment as a question about the compound from Renal impairment as a question about the documentation. They get answered by different people and only one of them is answerable here.