Granisetron

Granisetron stops certain chemicals in the body that can cause nausea and vomiting.

Granisetron is used to prevent nausea and vomiting that may result from medicine used to treat cancer (chemotherapy or radiation).

Granisetron may also be used for reasons not mentioned in this medication guide.

Follow all instructions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

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

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

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

Do not share this medicine with anyone else.

Granisetron is not likely to work 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.

Follow all instructions on your medicine label and package. Inform each of your healthcare providers about all your medical conditions, allergies, and all medicines you are taking.

You should not take granisetron if you are allergic to it.

To ensure granisetron is safe for you, inform 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 if granisetron will harm an unborn baby. Tell your doctor if you are pregnant.

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

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

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

Granisetron may cause serious side effects. Call your doctor right away if you experience:

• headache with chest pain and severe dizziness, fainting, or fast or pounding heartbeats;
• increased blood pressure--severe headache, ringing in your ears, anxiety, confusion, or 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, or fainting.

Common side effects of granisetron may include:

• headache, weakness;
• diarrhea, constipation;
• stomach pain, indigestion, or loss of appetite;
• sleep problems (insomnia); or
• fever, flu-like symptoms.

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

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 for the missed dose.

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

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

Granisetron can lead to a serious heart problem, especially if you take certain medicines at the same time. This includes antibiotics, antidepressants, heart rhythm medicine, antipsychotic medicines, and medicines for cancer, malaria, HIV or AIDS.

Using granisetron along with certain other medicines can result in high levels of serotonin in your body, known as "serotonin syndrome," which can be life-threatening. Inform your doctor if you are also using:

• 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 exhaustive. Other medications may interact with granisetron, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are included in this medication guide. Make sure to tell your doctor about all the medicines you are using, as well as any that you start or stop during your treatment with granisetron.