Reviewed on 3/31/2022

What Is Palonosetron and How Does It Work?

Palonosetron is a prescription medicine used in adults to help prevent nausea and vomiting that happens with certain anticancer medicines (chemotherapy).

  • Palonosetron is available under the following different brand names: Aloxi

What Are Dosages of Palonosetron?

Adult and pediatric dosage

Injectable solution: single-use vials

  • 0.05mg/mL

Prevention of Chemotherapy-induced Nausea & Vomiting

Adult dosage

  • 0.25 mg IV over 30 seconds x1, beginning 30 minutes before chemotherapy

Pediatric dosage

  • Children below 1 month: Safety and efficacy not established
  • Children between 1 month to 17 years: 20 mcg/kg IV infused over 15 minutes x1, beginning 30 minutes before chemotherapy; not to exceed 1.5 mg/dose

Prevention of Postoperative Nausea & Vomiting

Adult dosage

  • 0.075 mg IV infused over 10 seconds immediately before anesthesia

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”

What Are Side Effects Associated with Using Palonosetron?

Common side effects of Palonosetron include:

  • headache,
  • constipation, and
  • tiredness (fatigue).

Serious side effects of Palonosetron include:

  • serious allergic reactions, such as anaphylaxis- hives, swollen face, breathing trouble, chest pain,
  • Serotonin syndrome- agitation, seeing things that are not there (hallucinations), confusion, or coma, fast heartbeat, or unusual and frequent changes in blood pressure, dizziness, sweating, flushing, or fever, tremors, stiff muscles, muscle twitching, overactive reflexes, or loss of coordination, seizures, nausea, vomiting, and diarrhea.

Rare side effects of Palonosetron include:

  • Immune hypersensitivity reaction
This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.


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What Other Drugs Interact with Palonosetron?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Palonosetron has severe interactions with the following drug:
    • apomorphine
  • Palonosetron has serious interactions with at least 35 other drugs.
  • Palonosetron has moderate interactions with the following drugs:
    • dichlorphenamide
    • fenfluramine
    • peginterferon alfa 2b
  • Palonosetron has minor interactions with no other drugs. 

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Palonosetron?


  • Hypersensitivity to the drug, other selective 5-HT3 receptor antagonists (eg, granisetron), or any other component
  • Coadministration with apomorphine; combination reported to cause profound hypotension and loss of consciousness

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Palonosetron?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Palonosetron?”


  • Use caution in patients with congenital long QT syndrome or other factors that may prolong QT interval
  • Serotonin syndrome was reported with 5-HT3 receptor antagonists alone but particularly with concomitant use of serotonergic drugs including SSRIs, SNRIs, MAO inhibitors, lithium, tramadol, methylene blue IV, and mirtazapine
  • Hypersensitivity reactions, including anaphylaxis, were reported with or without known hypersensitivity to other 5-HT3 receptor antagonists
  • For chemotherapy, the drug should follow a specific schedule, and not be administered as needed
  • The drug is not recommended in PONV if the expectation for nausea or vomiting is very small; use only if the expectation is low or it is essential to avoid nausea and vomiting in the postoperative period

Pregnancy and Lactation

  • There are no available data on palonosetron HCl use in pregnant women to inform a drug-associated risk
  • Lactation
    • There are no data on the presence in human milk, effects on the breastfed infant or milk production; developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for drug and any potential adverse effect on the breastfed infant from palonosetron or underlying maternal condition.
Medscape. Palonosetron.

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