Exemestane
1 medicine
Exemestane is a steroidal aromatase inhibitor used to treat hormone-receptor-positive breast cancer in postmenopausal women. It reduces bone density and increases fracture risk, so bone health is monitored during treatment.
Key facts
- Exemestane (brand name Aromasin) is an aromatase inhibitor that lowers estrogen levels to treat hormone-receptor-positive breast cancer in postmenopausal women.
- It's taken once a day by mouth after a meal, usually as part of a five-year course, often following two to three years of tamoxifen.
- Exemestane reduces bone mineral density and increases the risk of osteoporosis and fracture. Bone density is checked before treatment starts and monitored during it.
- Seek urgent care for a bone that breaks with minimal trauma, sudden chest pain, or shortness of breath.
What exemestane treats
Exemestane treats hormone-receptor-positive breast cancer in women past menopause, either as adjuvant therapy to lower the chance of the cancer returning after surgery, or for cancer that has spread and no longer responds to tamoxifen. It is not used in women who are still menstruating, since it depends on the low, adrenal-derived estrogen production seen after menopause.
How exemestane works
After menopause the body still makes small amounts of estrogen using an enzyme called aromatase, and hormone-receptor-positive breast cancer cells use that estrogen to grow. Exemestane permanently disables aromatase, cutting the estrogen supply the tumour depends on and slowing or stopping its growth.
Before you take it
- Exemestane is contraindicated in pregnancy and must not be used by women who are or might become pregnant, since losing estrogen can seriously harm a developing baby.
- Tell your doctor about osteoporosis, previous fractures, or a strong family history of bone disease, since exemestane speeds up bone loss.
- Tell your doctor about cholesterol problems and liver disease, since exemestane can raise cholesterol and is processed by the liver.
- Avoid starting exemestane while still taking tamoxifen or estrogen-containing medicines, which can blunt its effect.
Side effects
Common effects include hot flushes, joint and muscle aches, fatigue, and nausea.
Stop and seek urgent medical care for any of these:
- A fracture after a minor fall or bump.
- Sudden chest pain, breathlessness, or leg swelling.
- Unusual bruising or bleeding.
Safety essentials
- Have a bone density scan before starting exemestane and at intervals during treatment. Your doctor may recommend calcium, vitamin D, or a bone-protecting medicine if your bone density falls.
- Take exemestane every day for the full length of the course your doctor recommends, since stopping early reduces its protection against cancer returning.
- Tell your doctor immediately if you think you could be pregnant. Exemestane must be stopped and reliable non-hormonal contraception used if you have not fully completed menopause.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.