Generic name: granisetron (oral) [ gra-NIS-e-tron ]
Drug class: 5HT3 receptor antagonists

Medically reviewed by Drugs.com. Last updated on Aug 5, 2024.

What is Kytril?

Kytril blocks the actions of chemicals in the body that can trigger nausea and vomiting.

Kytril is used to prevent nausea and vomiting that may be caused by medicine to treat cancer (chemotherapy or radiation).

Warnings

You should not use Kytril if you are allergic to granisetron or to similar medicines such as dolasetron (Anzemet), ondansetron (Zofran), or palonosetron (Aloxi).

Before taking Kytril, tell your doctor if you have liver disease, a heart rhythm disorder, an electrolyte imbalance (such as low levels of potassium or magnesium in your blood), or a personal or family history of Long QT syndrome.

Kytril is usually started up to 1 hour before chemotherapy. Tell your doctor if you forget to take the medication within the specified amount of time before your procedure.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

To make sure Kytril is safe for you, tell your doctor if you have:

• heart disease;

• a heart rhythm disorder;

• a personal or family history of long QT syndrome;

• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood); or

• if you have recently had stomach or intestinal surgery.

It is not known whether granisetron will harm an unborn baby. Tell your doctor if you are pregnant.

It is not known whether granisetron passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Kytril is not approved for use by anyone younger than 18 years old.

How should I take Kytril?

Take Kytril exactly as it was prescribed for you. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Kytril is usually taken only on the day of treatment with chemotherapy or radiation.

Your doctor may want you to take only one dose, up to 1 hour before chemotherapy or radiation.

For patients undergoing chemotherapy, a second dose of granisetron is sometimes given 12 hours after the first dose. Follow your doctor's dosing instructions very carefully.

Do not share this medicine with another person.

Kytril is not likely to be useful if you keep taking it during times when you are not receiving chemotherapy or radiation treatment.

Store at room temperature away from moisture, heat, and light.

Dosing information

Usual Adult Dose for Nausea/Vomiting--Radiation Induced:

2 mg orally given within 1 hour of radiotherapy.

Usual Adult Dose for Nausea/Vomiting--Chemotherapy Induced:

2 mg orally once daily with two 1 mg tablets given up to 1 hour before chemotherapy. Alternatlety, 1 mg given twice daily with the first 1 mg tablet given up to 1 hour before chemotherapy, and the second tablet 12 hours after the first tablet.

What happens if I miss a dose?

Tell your doctor if you forget to take your dose within 1 hour before chemotherapy or radiation. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Kytril side effects

Get emergency medical help if you have signs of an allergic reaction to Kytril: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• headache with chest pain and severe dizziness, fainting, fast or pounding heartbeats;

• increased blood pressure - severe headache, buzzing in your ears, anxiety, confusion, shortness of breath; or

• high levels of serotonin in the body - agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.

Common Kytril side effects may include:

• headache, weakness;

• diarrhea, constipation;

• stomach pain, indigestion, loss of appetite;

• sleep problems (insomnia); or

• fever, flu symptoms.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

What other drugs will affect Kytril?

Granisetron can cause a serious heart problem, especially if you use certain medicines at the same time, including antibiotics, antidepressants, heart rhythm medicine, antipsychotic medicines, and medicines to treat cancer, malaria, HIV or AIDS.

Taking granisetron together with certain other medicines can cause high levels of serotonin to build up in your body, a condition called "serotonin syndrome," which can be fatal. Tell your doctor if you also use:

• lithium;

• ritonavir;

• St. John's wort;

• an antidepressant;

• migraine headache medicine;

• a narcotic (opioid) medication or muscle relaxer; or

• other anti-nausea medications.

This list is not complete. Other drugs may interact with granisetron, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide. Tell your doctor about all medicines you use, and those you start or stop using during your treatment with Kytril.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Kytril only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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