Granisetron

(gran-iss-uh-tron)

Trade/other name(s): Kytril (injection, pill, liquid), Sancuso (patch)

Why would this drug be used?

Granisetron is used to prevent nausea and vomiting from chemotherapy and radiation. It is also used to prevent vomiting after surgery.

How does this drug work?

Granisetron is a member of a class of drugs called serotonin antagonists. It blocks two pathways of serotonin release to prevent chemotherapy-related nausea and vomiting. It binds to the serotonin receptors in the gastrointestinal tract (lining of the stomach and intestine). This keeps the vomiting center in the brain from being stimulated. Granisetron also responds to high levels of serotonin released after chemotherapy injures the cells lining the stomach.

Before taking this medicine

Tell your doctor…

• If you are allergic to anything, including medicines, dyes, additives, adhesive tapes, or foods.
• If you have high blood pressure, abnormal heart rhythm, heart block, or heart failure. In some people, granisetron can make these problems worse.
• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. Even though tests did not show any damage in pregnant animals, granisetron has not been tested in pregnant women.
• If you are breast-feeding. It is not known whether this drug passes into breast milk. If it does, it could harm the baby.
• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

No serious interactions are known at this time. But this does not necessarily mean that none exist. Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Granisetron can be given:

• as an injection (as a shot)
• as a pill or liquid that you swallow
• as a patch that is placed on the skin

As an injection it is given into a vein over 5 minutes, within 30 minutes before starting chemotherapy. As a pill or liquid it is given within the hour before starting chemotherapy or radiation therapy, and the dose may be repeated 12 hours after your treatment starts. The intravenous dose depends on your weight, though all adults usually get the same dose when given the pill or liquid.

As a patch, it is placed on the skin on the upper outer arm 24 to 48 hours before starting chemotherapy, and is left on for at least 24 hours after chemo is finished. It can be left on for up to 7 days. While you wear the patch and for 10 days afterward, keep the area covered to protect from sunlight or sun lamps.

Take this drug exactly as directed by your doctor. If you do not understand the instructions, ask your doctor or nurse to explain them to you. Store the medicine in a tightly closed container away from light, heat, and moisture. Keep out of the reach of children and pets.

Precautions

Tell your doctor or nurse right away if you notice itching, welts on your skin (hives), shortness of breath, dizziness, swelling of the face or mouth, or any trouble breathing or swallowing. These can be symptoms of an allergic reaction, which must be treated quickly.

Granisetron is only for short-term use during chemotherapy or radiation treatment. It is not to be taken regularly.

If you are using the patch, tell your doctor or nurse if you get any redness, rashes, bumps, blisters or itching at the patch site, especially if it spreads outside the place where the patch was or if it appears outside the patch site. You may need to stop using the patch.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.

Less common

• headache
• constipation
• diarrhea

Rare

• tiredness (fatigue)
• sleepiness
• high blood pressure
• fever
• high blood pressure
• abnormal heart rhythms
• skin reaction (if using the patch)*
• serious allergic reaction*

*See "Precautions" section for more detailed information.

There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 1993.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.