Xtandi is an anti-androgen. It works in the body by preventing the actions of androgens (male hormones).

Xtandi is used to treat prostate cancer

Xtandi is sometimes used when the cancer no longer responds to treatment, but has not spread to other parts of the body.

Xtandi is also used when the cancer has responded to treatment and has spread to other parts of the body (metastatic).

Although not for use by women, Xtandi can cause birth defects if the mother or the father is taking this medicine. Use a condom and one other form of birth control to prevent pregnancy during your treatment, and for at least 3 months after your treatment ends.

Xtandi may cause side effects on your spinal cord. Stop taking this medicine and call your doctor at once if you have severe low back pain, trouble walking or standing up, pain or weakness in your lower body, severe and worsening numbness or tingling, or sudden loss of bladder or bowel control.

Take Xtandi 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.

You may take Xtandi with or without food. Take the medicine at the same time each day.

You may need to take two 80mg tablets or four 40mg tablets or capsules at the same time once a day to get a full dose.

Swallow the Xtandi tablet or capsule whole. Do not break, chew, or crush a tablet. Do do not chew, open, or dissolve a capsule.

Prostate cancer is sometimes treated with a combination of drugs. Use all medications as directed by your doctor. Do not change your doses or medication schedule without your doctor's advice.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Usual Adult Dose for Prostate Cancer:

160 mg (four 40 mg capsules) orally once a day

Use: Metastatic castration-resistant prostate cancer

You should not use Xtandi if you are allergic to enzalutamide.

To make sure Xtandi is safe for you, tell your doctor if you have ever had:

• a seizure;

• a head injury, stroke, or brain tumor;

• heart disease, circulation problems;

• high blood pressure;

• diabetes; or

• high cholesterol or triglycerides (a type of fat in the blood).

Although not for use by women, Xtandi can cause birth defects if the mother or the father is taking this medicine. Do not use this medicine if you are pregnant.

If you are taking Xtandi and your sexual partner could become pregnant, use a condom and one other form of birth control to prevent pregnancy during treatment. Keep using these birth control methods for at least 3 months after your treatment ends. Tell your doctor at once if a pregnancy occurs while either parent is being treated with enzalutamide.

Although this medicine is not for use by women, it is not known whether enzalutamide passes into breast milk or if it could harm a nursing baby. You should not breastfeed while using this medicine.

Take the missed dose if you remember it later in the day. Skip the missed dose if it is almost time for your next day's dose. 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. An overdose could cause you to have a seizure.

Enzalutamide can increase your risk of seizure. Avoid any activity that could be dangerous if you have a seizure or lose consciousness.

Avoid driving or hazardous activity until you know how Xtandi will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Even without dizziness, taking Xtandi could increase your risk of falls or bone fractures. Avoid activities or situations that may lead to injury or falls.

Stop taking Xtandi and get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Xtandi may cause side effects on your spinal cord. Stop taking this medicine and call your doctor at once if you have:

• dizziness, spinning sensation;

• a seizure (black-out or convulsions);

• confusion, thinking problems, severe headache, vision problems;

• weakness, loss of consciousness;

• red or pink urine;

• heart problems - chest pain, shortness of breath (even with mild exertion);

• increased blood pressure - severe headache, blurred vision, pounding in your neck or ears, anxiety, nosebleed; or

• signs of a lung infection - fever, cough with yellow or green mucus, stabbing chest pain, wheezing, feeling short of breath.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common Xtandi side effects may include:

• feeling weak or tired;

• constipation, diarrhea;

• loss of appetite;

• flushing (redness, hot feeling);

• back pain, joint pain; or

• high blood pressure.

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.

Enzalutamide can increase your risk of having a seizure. This effect may be more likely if you also use certain other medicines that increase seizure risk. Tell your doctor if you are using an antibiotic, an antidepressant, asthma medication (a bronchodilator), birth control pills or hormone replacement, insulin or oral diabetes medicine, a steroid, or medicine to treat mental illness.

Many drugs can interact with enzalutamide. This includes 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 Xtandi. Give a list of all your medicines to any healthcare provider who treats you.