Letrozole Tablets (Femara) are mainly used for the treatment of hormone receptor-positive early-stage or advanced breast cancer in postmenopausal women. Proper use of letrozole is crucial for enhancing its therapeutic efficacy and reducing adverse reactions.

How to Use Letrozole Tablets (Femara)

Recommended Dosage

The standard recommended dosage of letrozole is 2.5 mg (one tablet) administered orally once daily.

The timing of administration is not affected by meals; the medication can be taken at any fixed time of the day to maintain stable blood drug concentrations.

Treatment Timing and Course

Adjuvant treatment for early-stage breast cancer: The usual duration of treatment is 5 years, or until disease recurrence.

Extended adjuvant treatment for early-stage breast cancer: Applicable to patients who have completed 5 years of tamoxifen treatment. The treatment course can last up to 5 years or be adjusted according to the doctor's advice.

Treatment for advanced breast cancer: Treatment should continue until disease progression or the occurrence of intolerable toxic reactions.

Patients must strictly follow the doctor's instructions and must not discontinue the medication or adjust the dosage on their own.

Dosage Adjustment of Letrozole Tablets (Femara)

Patients with Hepatic Impairment

Mild to moderate hepatic impairment (e.g., Child-Pugh Class A or B): No dosage adjustment is required.

Severe hepatic impairment (e.g., Child-Pugh Class C for cirrhosis): The recommended dosage is adjusted to 2.5 mg every other day to reduce the risk of drug accumulation in the body.

Patients with Renal Impairment

For patients with a creatinine clearance of ≥ 10 mL/min: No dosage adjustment is needed.

For patients with severe renal impairment (creatinine clearance < 10 mL/min): Clear clinical data are currently unavailable, and it is recommended to use the medication with caution under the guidance of a doctor.

Medication for Special Populations of Letrozole Tablets (Femara)

Pregnant Women

Letrozole has a confirmed toxic effect on the fetus, which can cause spontaneous abortion and congenital malformations. It is strictly contraindicated in pregnant women.

Women of childbearing potential should undergo a pregnancy test before initiating treatment and can only take the medication after confirming they are not pregnant.

Lactating Women

It is currently unknown whether letrozole is excreted in human milk. However, for safety reasons, it is recommended to discontinue breastfeeding during the medication period and for at least 3 weeks after stopping the medication.

Men and Women of Childbearing Age

Women: Effective contraceptive measures should be taken during the treatment period and for at least 3 weeks after the last dose.

Men: Letrozole may affect fertility. Men with fertility needs should consult a doctor before taking the medication.