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.

If you have any of these other conditions, you may need a dose adjustment or special tests to safely take Kytril:

• 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.

FDA pregnancy category B. Kytril is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether granisetron passes into breast milk or if it could harm a nursing baby. Do not use Kytril without telling your doctor if you are breast-feeding a baby.

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.

There may be other drugs that can interact with Kytril. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Get emergency medical help if you have any of these signs of an allergic reaction to Kytril: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as:

• fast or pounding heartbeats;
• fever, body aches, flu symptoms; or
• easy bruising or bleeding; unusual weakness.

Less serious Kytril side effects may include:

• headache;
• stomach pain or upset, loss of appetite;
• diarrhea or constipation;
• dizziness; or
• sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.