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Letrozole

    Brands

    DEA Class; Rx

    Common Brand Names; Femara

    • Antineoplastics, Aromatase Inhibitor

    Nonsteroidal oral aromatase inhibitor
    Used in postmenopausal women as adjuvant therapy for early breast cancer, extended adjuvant therapy after completion of 5 years of tamoxifen, and for advanced breast cancer; used off-label for infertility, idiopathic short stature in boys, and delayed puberty in boys
    Contraindicated in pregnancy; consider bone mineral density monitoring and cholesterol monitoring

    Breast Cancer

    Adjuvant treatment of early breast cancer

    • Postmenopausal women with hormone receptor positive early breast cancer

    Extended adjuvant treatment of early breast cancer

    • Postmenopausal women, who have received 5 yr of adjuvant tamoxifen therapy

    First and second-line treatment of advanced breast cancer

    • Postmenopausal women with hormone receptor positive or unknown, locally advanced or metastatic breast cancer
    • Also indicated for treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy

    Hypersensitivity to drug or excipients

    Pregnancy, premenopausal women

    • Diaphoresis (24%)
    • Bone pain (22%)
    • Hot flashes (19%)
    • Back pain (18%)
    • Dyspnea (18%)
    • Nausea (17%)
    • Night sweats (14%)
    • Cough (13%)
    • Fatigue (13%)
    • Constipation (10%)
    • Hypertension (8%)
    • Chest pain (8%)
    • Diarrhea (8%)
    • Decr wt (7%)
    • Edema (7%)
    • Breast pain (7%)
    • Bone fractures (6%)
    • UTI (6%)
    • Hypercalcemia (5%)
    • Headache (4%)
    • Weakness (4%)
    • Vomiting (3%)
    • Osteoporosis (2%)

    Use caution in liver impairment; administer a low dose to patients with hepatic impairment; effect of hepatic impairment on drug exposure in cancer patients with elevated bilirubin levels not determined

    Decreases in bone mineral density may occur; consider bone mineral density monitoring; increased risk of osteoporosis

    May cause dizziness, somnolence and fatigue; exercise caution when operating machinery

    May increase total serum cholesterol; consider cholesterol monitoring

    Avoid concomitant estrogens

    Risk of birth defects if given to pregnant women

    • Used off-label to induce ovulation
    • Health Canada & Novartis Canada warned against such use

    Based on post-marketing reports, findings from animal studies and mechanism of action, therapy can cause fetal harm and is contraindicated for use in pregnant women; in post-marketing reports, use during pregnancy resulted in cases of spontaneous abortions and congenital birth defects; however, data are insufficient to inform a drug-associated risk

    Not known if therapy is present in human milk; there are no data on effects on breastfed infant or milk production

    Adults

    2.5 mg/day PO per FDA-approved product labeling; however, single doses of 20 mg PO or doses of 7.5 mg/day PO have been used off-label for infertility.

    Geriatric

    2.5 mg/day PO for breast cancer.

    Adolescents

    Safe and effective use has not been established; however, 2.5 mg/day PO has been used in males with idiopathic short stature or constitutional delayed puberty.

    Children

    Younger than 9 years: Safe and effective use has not been established.
    9 years and older: Safe and effective use has not been established; however, 2.5 mg/day PO has been used in males with idiopathic short stature.

    Letrozole 

    tablet

    • 2.5mg