Fezol

Indications

Letrozole is used to treat hormone receptor-positive breast cancer in women who have gone through menopause:

• after surgery for early breast cancer, to lower the chance of it coming back (adjuvant treatment);
• after 5 years of Tamoxifen, to continue protection (extended adjuvant treatment);
• for advanced or spread (metastatic) breast cancer;
• before surgery, to shrink a tumour, as decided by the cancer specialist.

Specialists also use it for ovulation induction in some women with infertility, such as polycystic ovary syndrome. This use needs close medical supervision.

How It Works

Letrozole is an aromatase inhibitor. After menopause, most oestrogen in the body is made by the aromatase enzyme. Letrozole blocks this enzyme and lowers oestrogen levels, which slows the growth of breast cancers that depend on oestrogen.

Dosage and Administration

Breast cancer, adults: 2.5 mg once a day, at about the same time each day, with or without food. Early breast cancer is usually treated for 5 years, or as long as the specialist advises. Advanced breast cancer: continue while it keeps working.

Ovulation induction: only as prescribed by a fertility specialist, usually for a few days early in the cycle.

Kidney problems: no dose change is usually needed. Severe liver problems: the doctor may monitor more closely. Children: not for use.

If a dose is missed, take it when you remember unless the next dose is near; do not take two doses together.

Interactions

Tamoxifen lowers the level of Letrozole in the blood, so they are not taken together. Oestrogen-containing medicines (such as hormone replacement therapy or some birth control pills) work against Letrozole. Tell your doctor about all medicines, vitamins and herbal products you take.

Contraindications

• Women who have not yet gone through menopause (except under a specialist for infertility)
• Pregnancy and breastfeeding
• Allergy to Letrozole or any ingredient of the tablet

Side Effects

Common: hot flushes, joint and muscle pain, tiredness, sweating, headache, dizziness, nausea, swelling of the hands or feet, thinning hair, weight gain and raised cholesterol.

Long-term use can thin the bones (osteoporosis) and increase the risk of fractures. Less often: mood changes, trouble sleeping, high blood pressure, vaginal dryness or bleeding.

Get medical help at once for chest pain, sudden breathlessness, weakness on one side of the body, or a severe skin reaction.

Pregnancy and Lactation

Letrozole can harm an unborn baby and must not be used in pregnancy. Women who could become pregnant should use reliable contraception during treatment and for at least 3 weeks after the last dose. Do not breastfeed during treatment and for 3 weeks after the last dose.

Precautions and Warnings

• Your doctor may check bone density before and during treatment, and may advise calcium, vitamin D or other bone medicines.
• Cholesterol may need checking from time to time.
• Letrozole can cause tiredness and dizziness; take care when driving or using machines.
• Take extra care with severe liver disease.

Overdose

There is little experience of overdose. If too many tablets are taken, contact a doctor or go to hospital; treatment is supportive.

Therapeutic Class

Hormonal anticancer medicine (aromatase inhibitor).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.