Medically reviewed by Drugs.com. Last updated on Oct 17, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antineoplastic Agent
Pharmacologic Class: Aromatase Inhibitor
Uses for exemestane
Exemestane is used to treat early and advanced breast cancer in women who have already stopped menstruating (postmenopausal). It is usually used in women who have already received a cancer medication called tamoxifen.
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, which will limit the growth of the tumor.
Before you begin treatment with exemestane, you and your doctor should talk about the benefits exemestane will do as well as the risks of using it.
Exemestane is available only with your doctor's prescription.
Before using exemestane
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:
Tell your doctor if you have ever had any unusual or allergic reaction to exemestane or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of exemestane in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of exemestane in the elderly.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with 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. When you are taking exemestane, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using exemestane with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- St John's Wort
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of exemestane. Make sure you tell your doctor if you have any other medical problems, especially:
- Bone marrow problems (eg, lymphocytopenia) or
- Bone problems (eg, osteoporosis, broken bones)—Use with caution. May make these conditions worse.
Proper use of exemestane
Use exemestane only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. The exact amount of medicine you need has been carefully worked out. Using too much may increase the chance of side effects, while using too little may not improve your condition.
Exemestane comes with a patient information insert. Read and follow the instructions in the insert carefully. Talk to your doctor if you have any questions.
Take exemestane after a meal.
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.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For breast cancer in postmenopausal women:
- Adults—25 milligrams (mg) once a day.
- Children—Use is not recommended.
- For breast cancer in postmenopausal women:
If you miss a dose of exemestane, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using exemestane
It is very important that your doctor check your progress at regular visits to make sure that exemestane is working properly. Blood tests may be needed to check for unwanted effects. It is important for women to have regular gynecologic check-ups while taking exemestane.
It is unlikely that a postmenopausal woman may become pregnant. But, you should know that using exemestane while you are pregnant could harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test 7 days before you start using exemestane to make sure you are not pregnant. Use an effective form of birth control during treatment and for 1 month after the last dose. If you think you have become pregnant while using exemestane, call your doctor right away.
Exemestane may decrease bone mineral density when used for a long time. A low bone mineral density can cause weak bones or osteoporosis. If you have any questions about this, talk to your doctor.
Do not take exemestane if you are also using medicines that contain estrogen (eg, Premarin®), birth control pills or patches, or other medicines used for hormone replacement therapy.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.
Exemestane side 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 immediately if any of the following side effects occur:
- Cough or hoarseness
- difficult or labored breathing
- fever or chills
- lower back or side pain
- mental depression
- swelling of the hands, ankles, feet, or lower legs
- tightness in the chest
- Chest pain
- difficult, burning, or painful urination
- frequent urge to urinate
- sore throat
- unexplained broken bones
Incidence not known
- Abdominal or stomach pain
- clay-colored stools
- dark urine
- decreased urine output
- difficulty with speaking
- dilated neck veins
- double vision
- inability to move the arms, legs, or facial muscles
- inability to speak
- irregular breathing
- irregular heartbeat
- itching or rash
- loss of appetite
- slow speech
- unpleasant breath odor
- unusual tiredness or weakness
- vomiting of blood
- weight gain
- yellow eyes or skin
Some 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. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- general feeling of discomfort or illness
- general feeling of tiredness or weakness
- hot flashes
- increased sweating
- trouble sleeping
- Back pain
- bone pain
- burning, tingling, or prickly sensations
- decreased sense of touch
- increased appetite
- joint pain
- loss of hair
- runny nose
- stomach upset
- weakness, generalized
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
- Which is better - Aromasin or Femara?
- Aromasin vs Femara - how do they compare?
- How long do you need to take Aromasin?
- Should you take Aromasin with food?
More about exemestane
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Pricing & Coupons
- En Español
- 80 Reviews
- Drug class: aromatase inhibitors
- Other brands
Related treatment guides
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