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Nausea and Vomiting

Nausea is the sensation of needing to vomit; vomiting forcefully empties stomach contents. They are symptoms rather than a diagnosis and can result from gut, neurological, inner-ear, metabolic, pregnancy-related or medicine-related causes.

Thorazine

Chlorpromazine

50 · 100mg

Intended to address severe psychiatric symptoms by modulating dopaminergic pathways in the brain.

From$0.40/ tabletView

Zofran

Ondansetron

4 · 8mg

Developed to prevent nausea and to address vomiting associated with cancer treatments or surgical procedures.

From$1.17/ tabletView

Key takeaways

  • Replacing fluid and salts is often the immediate priority, especially with diarrhoea or repeated vomiting.
  • Antiemetics target different pathways and have distinct heart-rhythm, neurological and sedation risks.
  • Blood, green bile, severe pain, neurological symptoms or inability to keep fluids down are warning signs.

An antiemetic listing cannot identify the cause or safest option; age, pregnancy, heart rhythm, other medicines and hydration guide care.

What does assessment look for?

Timing, abdominal symptoms, bowel changes, headache, vertigo, pregnancy possibility and medicine changes narrow the cause. Examination assesses dehydration and signs of obstruction, infection or neurological disease.

When are antiemetics used?

Ondansetron is used in selected chemotherapy-related, postoperative and other settings. Chlorpromazine has broader dopamine-blocking effects and greater sedation and neurological considerations. Cause-specific treatment remains necessary; see digestive health for class context.

When to seek urgent care

Seek emergency care for vomiting blood or green bile, a rigid or severely painful abdomen, confusion, severe headache, recent head injury, fainting, very little urine or inability to keep fluids down.