Exemestane

What it is and how it works

Mechanism of Action Breast cancer cell growth may be estrogen-dependent. Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women. While the main source of estrogen (primarily estradiol) is the ovary in premenopausal women, the principal source of circulating estrogens in postmenopausal women is from conversion of adrenal and ovarian androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) by the aromatase enzyme in peripheral tissues. Exemestane is an irreversible, steroidal aromatase inactivator, structurally related to the natural substrate androstenedione.

Mechanism class: Aromatase Inhibitors

Indications

Exemestane tablets are an aromatase inhibitor indicated for: adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy . treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy . Adjuvant Treatment of Postmenopausal Women Exemestane tablets are indicated for adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy . Advanced Breast Cancer in Postmenopausal Women Exemestane tablets are indicated for the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy .

Dosage and administration (summary)

Recommended Dose: One 25 mg tablet once daily after a meal . Recommended Dose The recommended dose of exemestane tablets in early and advanced breast cancer is one 25 mg tablet once daily after a meal. adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy. the treatment of advanced breast cancer in postmenopausal women whose disease has progressed following tamoxifen therapy. Dose Modifications Concomitant use of strong CYP 3A4 inducers decreases exemestane exposure.

Contraindications

Exemestane tablets are contraindicated in patients with a known hypersensitivity to the drug or to any of the excipients. Patients with a known hypersensitivity to the drug or to any of the excipients .

Warnings and precautions

Reductions in bone mineral density (BMD) over time are seen with exemestane use . Routine assessment of 25-hydroxy vitamin D levels prior to the start of aromatase inhibitor treatment should be performed . Embryo-Fetal Toxicity: Can cause fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception ( 5.6 , 8.1 , 8.3 ). Reductions in Bone Mineral Density (BMD) Reductions in bone mineral density (BMD) over time are seen with exemestane use.

Pregnancy

Pregnancy Risk Summary Based on findings in animal studies and its mechanism of action , exemestane tablets can cause fetal harm when administered to a pregnant woman . Limited human data from case reports are insufficient to inform a drug-associated risk.

Storage and supply

Exemestane tablets are White colored, round, biconvex, film-coated tablets debossed with "X" on one side and "1" on other side. Each tablet contains 25 mg of exemestane. Exemestane tablets are packaged in HDPE bottles with a child-resistant screw cap, supplied in bottles of 30 tablets. 30-tablet HDPE bottle NDC 63629-2056-1. Store at 25°C (77°F).

Source: Exemestane (Exemestane) — US FDA prescribing information, 2024-05-29, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.