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Uses

What is exemestane used for?

Exemestane is commonly used to treat certain types of breast cancer, including estrogen receptor-positive breast cancer, in women after menopause.

Exemestane may also be used for other conditions as determined by your healthcare provider.

How does exemestane work (mechanism of action)?

Exemestane belongs to a class of medicines called  aromatase inhibitors. It works by blocking an enzyme called aromatase that helps produce estrogen in the body. By lowering the amount of estrogen, exemestane can help prevent the growth of tumors that rely on estrogen to grow.

How is exemestane supplied (dosage forms)?

Exemestane is available as Aromasin and generic exemestane as 25 mg oral tablets that are taken by mouth.

How should I store exemestane?

Exemestane should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of exemestane?

The most common side effects of exemestane are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Hot flashes or sweating
  • Headache
  • Joint pain
  • Nausea
  • Trouble sleeping
  • Tiredness
  • Increased appetite

There may be other side effects of exemestane that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of exemestane?

While less common, the most serious side effects of exemestane are described below, along with what to do if they happen.

Severe Allergic Reactions. Exemestane may cause allergic reactions, which can be serious. Stop taking exemestane and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Weak Bones. Taking exemestane for a long time may cause your bones to become weaker, leading to reduced bone density (osteopenia). It may also cause a more serious condition called osteoporosis, which can cause bones to break (fracture) more easily. If you take exemestane, your healthcare provider may monitor your bone density. Tell your healthcare provider if you break a bone, and get a bone mineral density test if one is ordered for you.

Warnings & Precautions

Who should not use exemestane?

Allergies to Ingredients. People who are allergic to any of the following should not take exemestane.

  • Exemestane
  • Aromasin
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific exemestane products they stock.

What should I know about exemestane before using it?

Do not take exemestane unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share exemestane with other people, even if they have the same condition as you. It may harm them.

Keep exemestane out of the reach of children.

Take your dose of exemestane after a meal.

Exemestane may affect your ability to become pregnant or get a partner pregnant. Talk with your healthcare provider if you have any concerns.

Ask your healthcare provider about your vitamin D level. You may need to take a supplement.

What should I tell my healthcare provider before using exemestane?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if exemestane is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

Other Medicines and Supplements. Exemestane may interact with other medicines and supplements. Before taking exemestane, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. Exemestane may cause harm to an unborn baby. A negative pregnancy test is necessary before starting treatment. If you can become pregnant, use effective birth control while you are taking exemestane and for 1 month after your last dose. Talk to your healthcare provider about your birth control options. If you become pregnant or think you may be pregnant, tell your healthcare provider right away.

Breastfeeding. Do not breastfeed while you are taking exemestane and for 1 month after your last dose. It is not known if exemestane passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed.

Interactions

Does exemestane interact with foods or drinks?

There are no known interactions between exemestane and foods or drinks.

There are no known interactions between exemestane and alcohol.

Does exemestane interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

 In particular, make sure that you discuss if you are using any of the following before taking exemestane.

  • An estrogen medicine, such as hormone replacement, certain birth control pills, or estrogen creams, rings, or suppositories
  • Phenytoin (Dilantin, Phenytek, and others), which is a medicine to control seizures
  • Rifampin, which is a medicine commonly used to treat an infection called tuberculosis
  • Carbamazepine (Tegretol, Carbatrol, and others), which is a medicine commonly used to treat seizures or nerve pain
  • Phenobarbital, which is a medicine that may be used to treat insomnia, migraines, or seizures
  • St. John’s wort, which is a supplement that may be used to treat depression

Some other medicines may alter blood levels of exemestane. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with exemestane. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much exemestane?

If you or someone else has used too much exemestane, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of exemestane?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.