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

Anzemet oral (taken by mouth) is used to prevent nausea and vomiting that may be caused by medicine to treat cancer (chemotherapy).

Anzemet may also be used for purposes not listed in this medication guide.

You should not take Anzemet if you are allergic to dolasetron. Anzemet can cause serious heart rhythm problems. You should not use this medication if you have a history of Long QT syndrome. Tell your doctor if anyone in your family has ever had this condition.

Anzemet is usually taken 1 hour before chemotherapy or 2 hours before surgery. 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.

Take Anzemet exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Anzemet is usually taken 1 hour before chemotherapy. Follow your doctor's instructions.

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

You should not take Anzemet if you are allergic to dolasetron.

To make sure you can safely take this medicine, tell your doctor if you have any of these other conditions:

• kidney disease;

• a serious heart condition such as "sick sinus syndrome";

• a heart rhythm disorder such as slow heartbeats, or atrial fibrillation (fast, irregular heart rhythm);

• personal or family history of long QT syndrome;

• congestive heart failure; or

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

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

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

Anzemet should not be given to a child younger than 2 years old.

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

Get emergency medical help if you have signs of an allergic reaction to Anzemet: hives; difficulty 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;

• a light-headed feeling, like you might pass out;

• slow heart rate, weak pulse, slow breathing;

• swelling in your hands or feet;

• little or no urinating; or

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

Common Anzemet side effects may include:

• mild headache;

• mild dizziness;

• drowsiness; or

• pain.

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.

Anzemet 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. Tell your doctor about all medicines you use, and those you start or stop using during your treatment with this medicine.

Taking Anzemet while you are using 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:

• medicine to treat depression;

• medicine to treat a psychiatric disorder;

• a narcotic (opioid) medication; or

• medicine to prevent nausea and vomiting.

This list is not complete and many other drugs can interact with dolasetron. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.