Is vomiting on dulaglutide dose-dependent or dose-rate dependent?

The case in front of me: vomiting · dulaglutide.

I suspect the usual explanation for this is wrong, or at least incomplete.

I am aware this may have a boring answer. I would still like the boring answer stated clearly.

So what is the mechanism, and how well established is it?

Answer first: vomiting is less common than nausea, is more strongly dose-related, and matters chiefly because of what it does to fluid and electrolyte balance.

Trial incidence for vomiting runs at roughly a third to a half of the nausea rate depending on agent and dose, and it is more concentrated in the escalation phase than nausea is.

Local reaction versus infection

Stated carefully, oral rehydration solutions work by glucose-coupled sodium co-transport, which continues to function when secretion is deranged. That is why the glucose-to-sodium ratio matters and a high-sugar sports drink is not equivalent.

Rinse rather than brush after an episode. Enamel is not replaceable.

The honest answer is that a day of it is unpleasant and that several days of it needs help.

Repeated vomiting is the mechanism behind most reported acute kidney injury in this class. The renal event is a volume event, not a direct toxicity.

Concretely, dental enamel erosion from repeated vomiting is a real if unglamorous consequence; rinsing with water rather than brushing immediately is the standard advice.

Vomiting rates in the trial programmes are reported separately from nausea and are consistently lower and more dose-dependent.

The renal risk here is volume, not toxicity. That is the mechanism to watch.

The underlying point is that the relevant risk chain is vomiting to volume depletion to reduced renal perfusion to a rising creatinine, which is how most acute renal events in this class occur.

An episode of vomiting several days after a dose, with no escalation and no other explanation, is not the typical pattern and deserves attention rather than tolerance.

A practical home formulation is about six level teaspoons of sugar and half a level teaspoon of salt in one litre of water, taken in small frequent sips rather than in volumes that provoke another episode.

Oral rehydration solution composition is standardised by the World Health Organization and rests on glucose-coupled sodium transport.

If fluids will not stay down for several hours, that is the threshold. Get help.

To be exact about it, this is the adverse effect where the honest advice is least about tolerance and most about knowing when to stop.

Warning signs that convert this from a nuisance to a clinical problem: inability to keep fluids down for more than a few hours, reduced urine output, dizziness on standing, confusion, or severe abdominal pain.

Anti-emetics interact with other medication and are a prescriber decision.

Do not escalate the dose while this is happening.

Start with frequency and duration, because an isolated episode after an escalation and repeated episodes over days are different problems.

Fluid lost in vomit carries sodium at roughly 60 millimoles per litre and potassium at rather less, so replacing it with plain water alone dilutes plasma sodium rather than restoring balance.

Electrolyte composition of gastric and intestinal secretions is published and is the basis for replacement calculations.

Research-use material is not approved for human use, and an unverified dose is an unquantifiable variable in any of this.

Small frequent sips of an oral rehydration solution, not large volumes of water.