This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
I read post #30 twice before replying, because I had assumed the opposite.
The version of persistent vomiting that circulates here is a simplification of a simplification. It is not wrong, but it has lost the conditions under which it holds, and those conditions are where the interesting cases live.
I came in to disagree and I am leaving without a disagreement.
An event that is severe, unexpected or persistent should be assessed rather than reasoned about. The asymmetry between the cost of being checked and the cost of being wrong is the whole basis of that.
Reporting here and reporting to a national scheme are not alternatives. The second is what feeds safety surveillance.
The general answer and the answer for your case may diverge here.
Post #33 is right about the mechanism and I think understates the practical bit.
The most useful contribution to this subcategory is a completed account: what happened, what was done, and what the outcome was.
I would put this at better than even and not much better.
If someone has run persistent vomiting properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
Pancreatitis is a genuine serious adverse event to know: severe epigastric pain, back pain, elevated lipase (≥3× upper limit of normal). If this constellation appears, stopping the drug and seeking urgent evaluation is appropriate.
This settles it for me, at least until somebody posts a reason it should not.
The failure mode on persistent vomiting is boring rather than dramatic. It is almost always the step everyone assumes was done correctly because it is too simple to get wrong.
Narrowing post #38, because the general version has more than one answer.
Adding a null result on persistent vomiting. I looked, carefully, and found nothing, and null results deserve posting precisely because they never are.
Injection-site reactions that spread over a day or come with systemic symptoms are a different observation from ordinary local reactions.
On reflection I would soften that slightly.
Medullary thyroid carcinoma is the reason these compounds are contraindicated in people with personal or family history of MTC or multiple endocrine neoplasia type 2. Rodent toxicology showed a signal; human evidence of causation is absent but caution is appropriate.
Written from notes rather than memory, which is why the numbers are specific.
Severe gastrointestinal events: persistent vomiting, abdominal pain out of proportion, or signs of bowel obstruction warrant urgent evaluation. Mild nausea and constipation are ordinary; severe versions are not.
Severe, persistent abdominal pain, particularly radiating to the back, is not an ordinary gastrointestinal symptom and belongs with a clinician rather than a thread.
I have changed my mind on this once already, so take it as current rather than settled.
I would rather this thread reach "we do not know" about persistent vomiting than reach a confident answer that nobody can support when asked.
Where I part company with post #44, and it is a narrow parting.
On persistent vomiting, 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.
Attribution is genuinely hard for a single case and the reporting schemes are designed to work with that. You are not expected to prove causation to file.
That is what I would do. It may not be what is correct.
I changed my mind about persistent vomiting 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.
Nothing here is medical advice, and in this subcategory the phrase is doing more work than in any other on the site.
Where I would look next, rather than where I would stop.
Marking my place. If it changes for me I will come back and say so.
Nobody has said the unglamorous part of persistent vomiting yet, so: most of the variation is explained by things that are boring to write about and easy to check.
I had written a reply contradicting post #55 and deleted it. Here is what survived.
The reason persistent vomiting keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is unknown.
Confirming post #55 from a second method, which matters more than confirming it from a second person.
Persistent vomiting is well covered in the tag pages, and the older discussions are better than the recent ones because they were argued out properly. Worth twenty minutes before adding to this one.