Netupitant and palonosetron
NK1 receptor antagonists
NK1 receptor antagonists
A fixed combination of an NK1 blocker and a 5-HT3 blocker, given before chemotherapy to prevent early and delayed nausea and vomiting.
Quick facts
- Group
- NK1 receptor antagonists
- Target
- Neurokinin-1 (substance P) receptor, plus the 5-HT3 receptor (palonosetron)
- Used for
- Prevention of acute
- Key effects
- Headache · Constipation · Weakness
- Monitor
- Nausea and vomiting · Bowel habit
- ATC
- A04AA55
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows netupitant bound to the human neurokinin-1 receptor.
Netupitant blocks neurokinin-1 receptors in the brainstem, so substance P cannot drive vomiting; this mainly protects against delayed nausea in the days after chemotherapy. Palonosetron blocks 5-HT3 receptors on vagal afferents and in the chemoreceptor trigger zone, which protects against acute nausea. Both drugs last a long time, so a single dose before chemotherapy covers several days. It is usually combined with dexamethasone.
- Chemotherapy releases serotonin and substance P
- Palonosetron blocks 5-HT3: acute phase protected
- Netupitant blocks NK1: delayed phase protected
Indications
- Prevention of acute and delayed nausea and vomiting with moderately or highly emetogenic cancer chemotherapy
Adverse effects
Common
- Headache
- Constipation
- Weakness, tiredness
- Heartburn, abdominal pain
- Skin redness
Contraindications
- Hypersensitivity to netupitant, palonosetron or any component
Key interactions
- SSRIs, SNRIs and other serotonergic drugs
- Risk of serotonin syndrome
- Strong CYP3A4 inducers (rifampicin)
- Lower netupitant levels and less protection
- Strong CYP3A4 inhibitors
- Higher netupitant levels
What is monitored
- Nausea and vomiting in the days after chemotherapy
- Bowel habit (constipation)
- Signs of serotonin syndrome when combined with serotonergic drugs
Administration and safety
- A single oral dose before chemotherapy, usually with dexamethasone.
- Because both parts act for days, it is not repeated on the following days of the same cycle unless ordered.
- The patient's other medicines are checked for serotonergic drugs and CYP3A4 interactions.
Pregnancy and breastfeeding
Human data are limited; use in pregnancy needs a clear benefit and is discussed with the oncology team.
Nursing care
- Give it on time before chemotherapy as ordered.
- Ask about antidepressants and other serotonergic drugs.
- Track nausea, vomiting, food and fluid intake for several days.
- Teach to report agitation, fever, stiffness or a racing or irregular heartbeat.
Pharmacokinetics
- Metabolism
- Netupitant mainly by CYP3A4; palonosetron partly in the liver
- Half-life
- Both components have long half-lives, netupitant longer than palonosetron
Test yourself
Think of the answer, then tap the question to see it.
Which phase of chemotherapy nausea does netupitant mainly prevent?
The delayed phase, by blocking NK1 receptors.
Which phase does palonosetron mainly cover?
The acute phase, by blocking 5-HT3 receptors.
Why is one dose enough for several days?
Both drugs have long half-lives.
Which drug interaction risk is checked with antidepressants?
Serotonin syndrome.
Connections
← Back to the class: NK1 receptor antagonists
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Netupitant and Palonosetron: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); RCSB PDB - 6HLP: Crystal structure of the Neurokinin 1 receptor in complex with the small molecule antagonist Netupitant (RCSB Protein Data Bank, 2026).
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Representative model, for educational purposes only.