What is Letrozole?
Letrozole, more commonly known by the brand name Femara, is an aromatase inhibitor that is used to 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 to treat early breast cancer in women who have experienced menopause and who have already been treated with a medication called tamoxifen (Nolvadex) for 5 years. 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 can be an effective off-label fertility treatment for women with ovulation problems, or for those with unexplained infertility. Off-label use is when a drug that’s approved to treat one condition is used to treat another condition.
How Letrozole works
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.
How should I take Letrozole?
Letrozole comes as a tablet to take by mouth once a day with or without food. Take letrozole at around the same time every day.
The typical dosing for letrozole (Femara) is 2.5 mg by mouth daily. Your dose may differ if you have liver problems.
The usual dosage of letrozole for inducing ovulation is 2.5 mg taken by mouth once daily for 5 days. Your doctor may ask you to start taking the drug either on day 3 or day 5 of your menstrual cycle. (Day 1 of your menstrual cycle is the first day of your period.) If you’re not having periods when starting Femara, your doctor will recommend when you should start taking the drug.
Sometimes your doctor may recommend that you take a higher dosage of Femara, such as 5 mg or 7.5 mg daily for 5 days.
The highest dose of Femara for fertility treatment hasn’t been determined. One 2011 study looked at using doses higher than the current standard dose to treat infertility. But more research is needed to know whether higher doses of Femara are more effective than lower doses. Be sure to always take the dosage of Femara that’s prescribed by your doctor.
Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take letrozole exactly as directed. 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. Continue to take letrozole even if you feel well. Do not stop taking letrozole without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.
Pros and cons of taking letrozole
There are several benefits of taking letrozole as there are side effects in this section, we shall be looking at the pros and cons of taking letrozole:
Pros
- It is an oral, anti-estrogen that helps in treating postmenopausal women with breast cancer.
- Letrozole can also be used to treat certain types of breast cancer whose hormone receptor status isn’t known.
- Letrozolehelp lower the risk of breast cancer coming back after it’s been treated with surgery.
- Letrozole helps lower the risk of breast cancer coming back after it’s been treated with both surgery and 5 years of tamoxifen (another cancer drug).
- In women that have polycystic ovary syndrome or anovulation (a problem with ovulation), letrozole can increase the chances of ovulating and pregnancy.
- In women that already ovulate on their own, treatment with letrozole can result in the development of multiple follicles and multiple eggs released.
Cons
- Studies have shown that the use of letrozole to induce ovulation has been associated with an increased risk of a child being born with birth defects.
- Although it is rare, women taking letrozole may develop a condition known as ovarian hyperstimulation syndrome (OHSS) which can manifest with symptoms ranging from bloating and diarrhea to extreme shortness of breath and chest pains.
Letrozole Side Effects
Mild side effects of letrozole oral tablets that have been reported include:
• belly pain or cramping
• bone, muscle, or joint pain
• dizziness
• feeling weak or having increased tiredness
• hair loss
• headache
• hot flashes
• sweating more than usual
• swelling, usually in your arms, feet, hands, or legs
• vaginal spotting
• weight gain
Mild side effects of many drugs may go away within a few days or a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.
Serious side effects
Serious side effects from letrozole oral tablets can occur, but they aren’t common. If you have serious side effects from letrozole oral tablets, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.
Serious side effects of letrozole oral tablets that have been reported include:
• allergic reaction*
• cardiovascular (heart or blood vessel) problems, such as heart attack
• high cholesterol
• stroke
• weakened bones
Letrozole may cause or worsen osteoporosis. It can decrease the density of your bones and increase the chance of broken bones and fractures. Talk to your doctor about the risks of taking this medication.
Letrozole may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
Which drugs or supplements interact with letrozole?
Letrozole is an anti-estrogen drug. Therefore, estrogen-containing products counteract the effect of letrozole. Some products that may interact with this drug include estrogens (such as Ethinyl estradiol, and conjugated estrogens), estrogen blockers (such as anastrozole, tamoxifen), and tibolone.
