In the U.S.—

In Canada—

• Antineoplastic

Exemestane (ex-uh-MESS-tane ) is a medicine that is used to treat breast cancer in women whose disease has progressed while they were taking tamoxifen ( ta-MOX-i-fen) .

Many breast cancer tumors grow in response to estrogen. Exemestane interferes with the production of estrogen in the body. As a result, the amount of estrogen that the tumor is exposed to is reduced, limiting the growth of the tumor. This medicine is meant to be used only by women who have already stopped menstruating.

Before you begin treatment with exemestane, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Exemestane is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For exemestane, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to exemestane. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Exemestane is meant to be used only by women who have experienced menopause and can no longer become pregnant, however, it is important to tell your doctor if you think you might be pregnant. If this medicine is taken by a pregnant woman for any reason it may cause harm to, and possibly even death of, the fetus.

Breast-feeding—It is not known whether exemestane passes into human milk. Studies in animals have shown that exemestane passes into rat milk. Because this medicine may cause serious side effects, breast-feeding is generally not recommended while you are taking it.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of exemestane in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine including the following:

• Estrogens—Exemestane may not work as well

• Kidney disease or
• Liver disease—It is not known whether moderate or severe kidney or liver disease may increase the chance of side effects during treatment

Use this medicine only as directed by your doctor. Do not use more or less of it, and do not use it more often than your doctor ordered. The exact amount of medicine you need has been carefully worked out. Taking too much may increase the chance of side effects, while taking too little may not improve your condition.

Dosing—

The dose of exemestane will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of exemestane. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets)
  • For breast cancer in postmenopausal women:
    • Adults—25 milligrams (mg) once a day after a meal.

Missed dose—

If you miss a dose of this medicine, do not take the missed dose at all and do not double the next one. Instead, go back to your regular dosing schedule and check with your doctor.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Cough or hoarseness;  difficult or labored breathing;  fever or chills;  increased blood pressure;  lower back or side pain ;  mental depression;  shortness of breath;  swelling of hands, ankles, feet, or lower legs;  tightness in chest 
  
  

• Less common
  • Chest pain;  difficult, burning, or painful urination;  frequent urge to urinate;  headache;  sore throat;  unexplained broken bones;  wheezing  
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Abdominal or stomach pain;  anxiety;  constipation;  diarrhea;  dizziness;  general feeling of discomfort or illness;  general feeling of tiredness or weakness ;  hot flashes;  increased sweating;  loss of appetite;  nausea and vomiting;  pain;  trouble in sleeping 
  
  

• Less common
  • Back pain;  bone pain;  burning, tingling or prickly sensations;  confusion ;  decreased sense of touch;  increased appetite;  itching;  joint pain;  loss of hair;  rash;  runny nose;  stomach upset;  weakness, generalized 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.