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Flutamide

(floo-tuh-mide)

Trade/other name(s): Eulexin

Why would this drug be used?

Flutamide blocks the action of androgens (male hormones) and is used to treat advanced prostate cancer.

How does this drug work?

Flutamide belongs to the group of drugs known as hormone antagonists. It stops cancer cells that depend on male hormones from growing.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have any inherited blood condition such as hemoglobin M disease or G6PD deficiency, which causes problems with certain medicines (sulfa, anesthetics such as lidocaine, and the heart medicine nitroglycerin), nitrates, nitrites, or foods such as broad beans (fava beans). Flutamide is more likely to cause an unusual complication in these people in which blood cells are unable to carry oxygen, a serious condition known as methemoglobinemia.
  • If you smoke. People who smoke are more likely to have problems with blood cells becoming unable to carry oxygen, as noted above.
  • If you have any medical conditions such as kidney disease, liver disease (including hepatitis), heart disease, congestive heart failure, diabetes, gout, or infections. These conditions may require that your medicine dose, regimen, or timing be changed.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may cause birth defects if either the male or female is taking it at the time of conception or during pregnancy. This drug is only approved for use in men, and has not been studied in women. Check with your doctor about what kinds of birth control can be used with this medicine.
  • If you are breast-feeding. It is not known whether this drug passes into breast milk. If it does, it could harm the baby.
  • If you think you might want to have children in the future. This drug may reduce fertility. Talk with your doctor about the possible risk with this drug and the options that may preserve your ability to have children.
  • 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

This drug can increase the risk of bleeding when taken with warfarin (Coumadin, a "blood thinner").

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

Grapefruit or grapefruit juice may raise the level of this drug in your body. This can worsen any bad effects the drug may have on you and may increase its action in a harmful way. Check with your doctor, nurse, or pharmacist about whether other 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?

Flutamide is a pill you take by mouth 3 times a day, with doses about 8 hours apart. It can be taken with or without food. When used for prostate cancer treatment flutamide is usually started at the same time as another drug in injection form called a luteinizing hormone-releasing hormone (LHRH) analog, which helps stop the body from making testosterone.

The dose of flutamide is the same for everyone. Take this drug with a glass of water, exactly as your doctor tells you. If you do not understand the instructions, ask your doctor or nurse to explain them to you.

Keep the medicine in a tightly closed container away from heat and moisture and away from children and pets.

Precautions

Call your doctor right away if you notice your urine turning dark or brown, or if your skin takes on a blue or grayish cast. A few men who take flutamide have a rare effect in which their blood cells cannot carry oxygen, called methemoglobinemia. This is more likely to happen in men who smoke and those who have an inherited condition called G6PD deficiency. It may also cause the lips and the inside of the mouth to look a little brown in color, and cause shortness of breath during activity. Those who have this problem must stop the drug and get emergency help.

Flutamide can cause severe liver damage in a few people. Your doctor will likely check your blood so that if this starts to happen, it can be found early to reduce the risk of permanent damage. Call your doctor right away if you notice nausea, vomiting, fatigue, poor appetite, dark urine, yellowing skin or eyes, or tenderness under the right side of the rib cage. Keep all your appointments for lab work and doctor visits.

It is important to keep taking flutamide, even if you feel well. If you are bothered by side effects, talk to your doctor or nurse to find out if the problems are serious. Many side effects can be managed with help from your doctor.

Urine may look greenish or a bit orange in color while taking this drug as the body gets rid of it. But if the urine becomes dark or brown (the color of cola or strong tea) call your doctor.

This drug has not been tested in women or children and is not recommended for their use.

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.

Common

  • hot flashes with sweating
  • impotence (erectile dysfunction)

Less common

  • decreased sexual interest
  • decreased sexual ability
  • swelling or tenderness of breasts
  • diarrhea
  • nausea
  • skin rash

Rare

  • liver problems with symptoms such as nausea, vomiting, yellowing of skin or eyes, poor appetite, dark urine*
  • low oxygen in the blood, which can cause shortness of breath with exercise, and change the color of skin and urine (methemoglobinemia)*

*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 1989.

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.

Last Medical Review: 12/07/2009
Last Revised: 12/07/2009