Description:

Letrozole is a medication primarily used in the treatment of hormonally-responsive breast cancer in postmenopausal women. It belongs to a class of drugs known as aromatase inhibitors. Letrozole is also used off-label for ovulation induction in women with infertility, particularly those with polycystic ovary syndrome (PCOS).

Mechanism of Action:

Letrozole works by inhibiting the enzyme aromatase, which is responsible for converting androgens (produced by the adrenal glands) into estrogen. By blocking estrogen synthesis, Letrozole reduces estrogen levels in the body, which is beneficial in the treatment of hormone-receptor-positive breast cancer as estrogen fuels the growth of these tumors.

Indications:

• Breast Cancer: Letrozole is indicated for the adjuvant treatment of early-stage hormone-receptor-positive breast cancer in postmenopausal women. It is also used in the treatment of advanced or metastatic breast cancer.
• Ovulation Induction: Letrozole is used off-label in the treatment of infertility to induce ovulation in women with anovulatory disorders, such as PCOS.

Dosage and Administration:

• The dosage of Letrozole is typically determined by the healthcare provider based on the specific condition being treated, the patient’s medical history, and other factors.
• For breast cancer treatment, Letrozole is usually taken orally once daily, with or without food.
• For ovulation induction, Letrozole is typically taken for five days starting on the second, third, fourth, or fifth day of the menstrual cycle.

Potential Side Effects:

• Common side effects of Letrozole may include hot flashes, night sweats, fatigue, headache, and musculoskeletal pain.
• Less common side effects can include vaginal dryness, mood changes, and gastrointestinal symptoms such as nausea or constipation.
• Rare but serious side effects may include bone thinning (osteoporosis) and an increased risk of fractures.

Precautions:

• Letrozole should not be used in premenopausal women, pregnant women, or women with a history of hypersensitivity to the drug.
• It may interact with certain medications, and patients should inform their healthcare provider of all medications, supplements, and herbal products they are taking.
• Letrozole can cause fetal harm if used during pregnancy and should be avoided in women who are or may become pregnant.

Monitoring:

• Regular monitoring by a healthcare provider is important to assess the effectiveness of the treatment, manage side effects, and monitor for any complications.
• Bone density may be monitored in patients receiving long-term Letrozole therapy to assess for bone thinning and osteoporosis.

Letrozole is an important medication in the treatment of hormonally-responsive breast cancer and infertility. Its use should be under the supervision of a qualified healthcare professional, and patients are advised to follow their healthcare provider’s recommendations closely for optimal safety and efficacy.