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What is Aromasin® ? (exemestane)

Aromasin is an aromatase inhibitor (a type of hormone therapy) that is used for1:

  • The adjuvant (after initial therapy) treatment of postmenopausal women with estrogen-receptor positive (ER+) early breast cancer who have previously received tamoxifen for 2 to 3 years and are changing therapies to Aromasin to finish 5 years in a row of adjuvant hormone therapy
  • The treatment of advanced breast cancer in postmenopausal women who experienced disease progression after treatment with tamoxifen

Aromasin is marketed by Pfizer. There are several generic versions of this medication available under the name exemestane tablets.

What is the ingredient in Aromasin?

The active ingredient in Aromasin is exemestane, an aromatase inhibitor.1

How does Aromasin work?

Breast cancers are classified as hormone receptor positive (HR+) if they have hormone receptors on the surface of their cells. In HR+ breast cancers, hormones such as estrogen can bind to the receptors and stimulate the cancer cell’s growth.

In postmenopausal women, estrogens in the body are created when androgens are converted to estrone and estradiol by the enzyme aromatase. Aromasin is an aromatase inhibitor. It helps to block the action of aromatase, significantly lowering the levels of estrogen in the body.1

What are some of the possible side effects of Aromasin?

The most common side effects experienced by patients with advanced breast cancer taking Aromasin include1:

When used as a treatment in early breast cancer, the most common side effects experienced with Aromasin include hot flushes, fatigue, joint pain, headache, insomnia, and increased sweating.1

A potentially serious side effect experienced by patients taking Aromasin is bone loss, which may lead to osteoporosis and/or bone fractures.2

Less commonly, women taking Aromasin have experienced chest pain, heart failure, or stroke.2

Things to know about Aromasin

Aromasin should only be used in women who are postmenopausal. It should not be used in women who are pregnant or breastfeeding, as it may cause harm to an unborn baby or breastfeeding child. Women who can become pregnant should use effective contraception while taking Aromasin and for at least one month after the last dose of Aromasin. Patients should discuss effective contraception methods with their doctor. Additionally, women should not breastfeed while taking exemestane and for at least one month after the last dose of Aromasin.1

Aromasin should not be used by anyone who has a known allergy or hypersensitivity to the medication.1

Before starting treatment with Aromasin, patients should talk to their doctor about all medications (prescription and over-the-counter), vitamins, and herbal supplements they are taking, especially if they are taking any medication that has estrogen in it, like oral contraceptives or hormone replacement therapy. Some medications or supplements may interfere with each other and may cause side effects.2

Before beginning treatment with Aromasin and throughout therapy, women may receive bone scans to monitor their bone health and will typically have their vitamin D levels checked prior to starting treatment with Aromasin.2

Women should talk to their doctor about all their health conditions before starting treatment with Aromasin, including any liver or kidney problems.2

Dosing information

Aromasin comes in a tablet that contains 25 mg of exemestane. It should be taken by mouth once daily after a meal.1

For more information, read the full prescribing information of Aromasin.

Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their Aromasin regimen.

  1. Aromasin prescribing information. Available at Accessed 9/27/18.
  2. Aromasin product website. Available at Accessed 9/27/18.