Drug reference

Exemestane

Aromatase Inhibitor · Breast cancer treatment

Also known as Aromasin

Aromatase InhibitorBreast cancer treatmentATC null

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

1 major

SEVERE in our sources

PREGNANCY

Avoid during pregnancy.

FDA category + note

Top interactionssee all 2 →

ThalidomideSevereDatabaseDDInter

Mechanism

Exemestane is a steroidal, type I, aromatase inhibitor. It acts as a substrate analog that irreversibly inactivates aromatase, thereby blocking the production of estrogens. This mechanism reduces both circulating and local levels of estrogens.

Indications

Adjuvant treatment of oestrogen-receptor-positive early breast cancer in postmenopausal women following 2 3 years of tamoxifen therapyAdvanced breast cancer in postmenopausal women in whom anti-oestrogen therapy has failedtreatment of breast cancerbreast cancer (ER expression)Adjuvant treatment of postmenopausal women (natural or in conjunction with ovarian function suppression) with HR+ breast cancer (either as initial therapy or after tamoxifen)Treatment of postmenopausal women (natural or in conjunction with ovarian function suppression) with HR+ advanced and metastatic breast cancer (sometimes in combination with mTOR inhibitor everolimus)Advanced ER+/PR+ breast cancer in premenopausal women when combined with GnRH agonistsEarly breast cancer (reducing the risk of disease progression when substituted for tamoxifen as adjuvant therapy)Advanced breast cancerChemoprevention for postmenopausal women at moderate-high risk for breast cancer (reduces incidence by about 50%)Adjuvant therapy for postmenopausal women with ER-positive breast cancer (5 years, provides modest but statistically significant superior outcome compared with tamoxifen)Used with LHRH agonist for higher risk premenopausal womenAs monotherapy, restricted to postmenopausal women

Dosing

Adult: 25 mg daily by mouth
Renal adjustment: Manufacturer advises caution.
Hepatic adjustment: Manufacturer advises caution.

Pharmacokinetics

Half-life

Terminal half-life of approximately 24 hours.

Bioavailability

Rapidly absorbed from the gastrointestinal tract; absorption is increased by 40% after a high-fat meal.

Metabolism

Extensively metabolized in the liver, ultimately to inactive metabolites; one metabolite, 17-hydroxyexemestane, has weak androgenic activity that may contribute to antitumor activity.

Excretion

Metabolites are excreted in the urine, but no dosage adjustments are recommended in patients with renal dysfunction.

Contraindications

Not indicated for premenopausal women

Side effects

Common

Alopeciaappetite decreasedarthralgiaastheniabone fracturecarpal tunnel syndromeconstipationdepressiondiarrhoeadizzinessgastrointestinal discomfortheadachehot flushhyperhidrosisinsomnialeucopenianauseaosteoporosispainparaesthesiaperipheral oedemaskin reactionsthrombocytopeniavomitinghot flashesVasomotor symptoms (hot flashes)ArthralgiasVaginal drynessSexual dysfunctionSimilar to other AIsPostmenopausal symptoms

Serious