Peak-Dose Opioid Nausea Pattern — SCE Palliative Medicine MCQ

Instant feedback + full explanation. One question, done properly.

ModerateNausea & VomitingPeak-Dose Opioid Nausea PatternSCE Palliative Medicine

A 68‑year‑old woman with advanced ovarian cancer on a CSCI of morphine develops acute nausea shortly after a dose increase. She experiences no nausea between bolus doses. What pattern of nausea does this suggest?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Peak‑dose nausea (transient CTZ stimulation)

The temporal pattern—nausea occurring acutely after dose increase but absent between doses—is characteristic of peak‑dose nausea due to transient stimulation of the chemoreceptor trigger zone (CTZ) as opioid plasma levels spike and then stabilise. NICE guidance notes that opioid‑induced nausea at dose increase is typically transient. CTZ involvement is a well‑recognised mechanism in opioid nausea. Other causes: raised ICP would present with neurological signs; vestibular nausea is movement‑related and persistent; gastric stasis causes ongoing nausea; constipation develops over days rather than immediately.

Reference: NICE CG140 (2016): opioid‑induced nausea likely transient at dose increase; MHRA opioids GI adverse effects: CTZ mechanism; UK practice aligned.