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What is the reported incidence of reflux on tirzepatide in SURMOUNT-3?

Asked 6 Mar 2025Modified 15 months agoViewed 29k times
24

Details up front: reflux · tirzepatide · SURMOUNT-3.

This is presented as though it settles something, and I am not convinced it does.

I have two documents that appear to disagree, which is what prompted this.

Which parts of this are informative and which are decoration?

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askedtwo_two_micron9.3k166 Mar 2025

5 Answers

Accepted answer first, then by votes
49

Accepted answer

Take it from the SURMOUNT-3 adverse-event table by arm, and check the unit before you use it. An incidence can be the proportion of participants who reported the event at least once, or the count of events divided by exposure time, and the two differ by however many people had it repeatedly. Then subtract the placebo arm, because the untreated rate is not zero. And read the discontinuation column beside it: an event that made people leave the trial is under-counted at every later visit, so a low late-timepoint incidence can mean the event was severe rather than rare.

Answer first: the gastrointestinal effects in this class share one mechanism — slowed gastric emptying plus central signalling — and present as nausea, fullness, reflux, constipation or diarrhoea depending on the person.

Reflux occurs because a slower-emptying stomach retains volume for longer against a lower oesophageal sphincter that has not changed. Smaller meals and not lying down within a few hours are the direct responses.

Anticipating a slower-than-label titration from the start is a legitimate approach and costs only time, since the exposure ceiling is the same.

Gastric emptying studies in this class quantify the delay directly and document its attenuation with continued exposure to the long-acting agents.

Slow the titration first. It is the intervention with the best evidence and the lowest cost.

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answered · acceptedtriple_agonist_q57k3814 Apr 2025
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53

The relevant physiology is that gastric emptying slows substantially and then partially normalises with continued exposure at a stable dose.

Gastric emptying of a solid meal can be delayed substantially at initiation. The effect is largest early and attenuates over weeks for the long-acting agents, which is the mechanistic basis for the titration schedule.

Specifically, symptoms that appear for the first time at a stable dose after months are not the ordinary pattern and warrant looking for another explanation.

Dietary fat slowing gastric emptying is basic gastrointestinal physiology and independent of any drug effect.

Smaller meals, less fat, fluids between rather than with. In that order.

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answeredDr_Lena_Ostrowska38k2722 Mar 2025
36

The honest answer is that the first eight weeks are the hard part and that most people who get through them stop having the conversation.

The practical hierarchy of interventions: slow the titration, reduce meal size, reduce fat, separate fluids from meals, and only then consider symptomatic treatment.

Discontinuation for gastrointestinal effects in the trials runs in the low single-figure percentages, which means the great majority of people who experience these effects continue.

Trial-reported incidence and discontinuation rates for gastrointestinal effects are published per agent and per dose and are the appropriate figures to quote.

Everything except constipation attenuates. Plan differently for that one.

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answeredgrainne_ahearn50k3811 Mar 2025
3This should be linked from the help pages. – ruaidhri_o_shea 4 months ago
4Adding a vote because this deserves more of them. – u100_marks 5 months ago
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23

Answering this needs the titration history, because going faster than the schedule is the single largest modifiable factor.

Fat is the macronutrient that slows emptying most on its own, so a high-fat meal on top of pharmacologically delayed emptying is the combination that produces the worst episodes.

Four-weekly titration intervals in the licensed schedules were selected to allow tolerance between escalations.

The caveat is that severe persistent symptoms, particularly with dehydration or severe pain, are clinical and not a matter of waiting them out.

Most people who report these effects continue. The discontinuation rate is low.

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answeredstopper_core28k1273 Apr 2025
16

This is the group of effects that drives almost all discontinuation in the trial programmes.

Symptom prevalence in trials, broadly: nausea a quarter to a half, diarrhoea and constipation each roughly ten to twenty per cent, vomiting rather less, with all rates rising with dose.

Research-use compounds are not approved for human use.

New symptoms at a stable dose after months need a different explanation.

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answeredten_mg_vial31k1386 May 2025
6The red-flag list should be higher up the answer, not at the bottom. – Dr_Colm_Fitzhenry 3 months ago
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Your answer

Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.

Not medical advice. Research-use-only compounds are not approved for human use.