Letrozole is used treat early breast cancer in women who have experienced menopause (change of life; end of monthly menstrual periods) and who have had other treatments, such as radiation or surgery to remove the tumor. .
Letrozole is also used in women who have experienced menopause as a first treatment of breast cancer that has spread within the breast or to other areas of the body or in women whose breast cancer has worsened while they were taking tamoxifen. Letrozole is in a class of medications called nonsteroidal aromatase inhibitors. It works by decreasing the amount of estrogen produced by the body. This can slow or stop the growth of some types of breast cancer cells that need estrogen to grow.
Letrozole comes as a tablet to take by mouth once a day with or without food. Take this product at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Do not take more or less of it or take it more often than prescribed by your doctor.
You may need to take letrozole for several years or longer. Do not stop taking letrozole without talking to your doctor.
Letrozole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- hot flushes
- night sweats
- loss of appetite
- stomach pain
- changes in weight
- muscle, joint, or bone pain
- excessive tiredness
- swelling of the hands, feet, ankles, or lower legs
- difficulty falling asleep or staying asleep
- vaginal bleeding or irritation
- breast pain
- hair loss
- blurry vision