- Body system
- Gastrointestinal
- Name stem
- -setron
- Drug cards
- 3 in this guide
Drugs in this class
Other examples: Granisetron, Palonosetron, Prochlorperazine, Scopolamine, Aprepitant, Meclizine.
How antiemetics work
Serotonin 5-HT3 antagonists (-setron), dopamine antagonists (metoclopramide, prochlorperazine), antihistamines and anticholinergics (promethazine, meclizine, scopolamine) and NK1 antagonists (aprepitant) act on the vomiting pathways.
Uses
- Chemotherapy-induced nausea and vomiting
- Postoperative nausea
- Motion sickness
- Gastroparesis (metoclopramide)
Adverse effects
- Headache, constipation and QT prolongation (ondansetron)
- Extrapyramidal symptoms and tardive dyskinesia (dopamine antagonists)
- Sedation and anticholinergic effects (antihistamines)
- Tissue injury with injection (promethazine)
Nursing considerations
- Give before chemotherapy as scheduled to prevent nausea.
- Monitor QT risk factors with ondansetron.
- Assess for movement disorders with metoclopramide and phenothiazines.
Patient teaching
- Avoid driving if drowsy.
- Report abnormal movements.
- Scopolamine patch: apply behind the ear and wash hands after handling.
Antiemetics NCLEX practice questions
Answer each question to see the rationale.
3 questions. Choose an answer to see the rationale.
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Which antiemetic carries a boxed warning for tardive dyskinesia?
Show answer
Answer A: Metoclopramide Metoclopramide can cause tardive dyskinesia; treatment beyond 12 weeks should be avoided.
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What is the preferred parenteral route for promethazine?
Show answer
Answer A: Deep intramuscular Deep IM is preferred. Subcutaneous and intra-arterial injection are contraindicated because of severe tissue injury.
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A patient receiving ondansetron has a low potassium level. Why is this a concern?
Show answer
Answer B: It increases the risk of QT prolongation Hypokalemia increases the risk of QT prolongation and torsades de pointes with ondansetron.
Frequently asked questions
What are antiemetics?
Antiemetics prevent and treat nausea and vomiting. Ondansetron prolongs the QT interval, metoclopramide can cause tardive dyskinesia, and promethazine can destroy tissue if injected wrongly.
How do antiemetics work?
Serotonin 5-HT3 antagonists (-setron), dopamine antagonists (metoclopramide, prochlorperazine), antihistamines and anticholinergics (promethazine, meclizine, scopolamine) and NK1 antagonists (aprepitant) act on the vomiting pathways.
What are examples of antiemetics?
Ondansetron, Metoclopramide, Promethazine, Granisetron, Palonosetron, Prochlorperazine, Scopolamine and Aprepitant.
What are the nursing considerations for antiemetics?
Give before chemotherapy as scheduled to prevent nausea. Monitor QT risk factors with ondansetron.