Femara (chemical name: letrozole) is an aromatase inhibitor approved by the U.S. Food and Drug Administration (FDA) to treat:
- postmenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer right after surgery (or possibly chemotherapy and radiation) to reduce the risk of the cancer coming back
- postmenopausal women diagnosed with hormone-receptor-positive early-stage breast cancer who have taken 5 years of tamoxifen to reduce the risk of the cancer coming back
- postmenopausal women diagnosed with advanced-stage or metastatic hormone-receptor-positive breast cancer
Femara won’t work on hormone-receptor-negative breast cancer.
Femara is a pill taken once a day. Most doctors recommend taking Femara at the same time each day.
In 2011, the FDA gave approval for 11 pharmaceutical companies to make a generic version of Femara, which may go by the chemical name letrozole.
You should not take Femara if you are breastfeeding, pregnant, trying to get pregnant, or if there is any chance that you could be pregnant. Femara may cause damage to developing embryos. You should use an effective non-hormonal type of birth control — such as condoms, a diaphragm along with spermicide, or a non-hormonal I.U.D. – while you are taking Femara. Ask your doctor which type of non-hormonal birth control would be best for you, as well as how long you should use this type of birth control after you stop taking Femara.
- Benefits of Femara
- Side effects of Femara
- How long do I take Femara?
- Does insurance cover Femara?
- How does this medication work? What will it do for me?
- What form(s) does this medication come in?
- How should I use this medication?
- Who should NOT take this medication?
- What side effects are possible with this medication?
- Are there any other precautions or warnings for this medication?
- What other drugs could interact with this medication?
- My Deep, Dark Femara Secret
Benefits of Femara
Two large studies have shown the benefits of Femara.
The international BIG 1-98 trial, started in 1998, compared Femara to tamoxifen after surgery in postmenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer. The results showed that Femara was better than tamoxifen for:
- increasing the time before the cancer comes back in those who experience recurrence
- reducing the risk of the cancer spreading to other parts of the body
The MA-17 study, conducted in Canada, looked at whether taking Femara for 5 years AFTER taking tamoxifen for 5 years (for a total of 10 years of hormonal therapy) could lower the risk of the cancer coming back in postmenopausal women diagnosed with hormone-receptor-positive, early-stage breast cancer. The results showed that Femara:
- reduced the risk of the cancer coming back
- reduced the risk of the cancer spreading to another part of the body
compared to not taking Femara after 5 years of tamoxifen.
Side effects of Femara
Because Femara lowers the amount of estrogen in the body, less estrogen reaches bone cells, which can lead to bone thinning and weakening and a higher-than-average risk of broken bones. This side effect can be very troubling for some women. If you have osteoporosis, your doctor may recommend that you take tamoxifen rather than Femara because of this possible side effect.
Other common side effects of Femara are:
- bone and joint pain
- higher cholesterol
- hot flashes
- weight gain
Some women may have other side effects while taking Femara:
- swelling of hands, feet, ankles, or lower legs
- loss of appetite
- difficulty sleeping
- vaginal bleeding
- breast pain
- dry skin
Some side effects may mean that you’re having an allergic reaction to Femara. If you have shortness of breath or chest pain, call your doctor immediately.
How long do I take Femara?
In most cases, you’ll take Femara for 5 years. Doctors may recommend that some women take it for a longer period of time.
Does insurance cover Femara?
While costs vary, Femara can cost several hundred dollars per month. Femara also is available as a generic medicine, which is usually less expensive. If you have health insurance, check with your insurance company to see if and how much of the cost of Femara is covered. If you don’t have health insurance or your insurance doesn’t cover the cost of Femara, ask your doctor or nurse about programs in your area that may be able to help. Also, ask your doctor about prescribing a generic version of Femara, which may be less expensive.
Novartis, the company that makes Femara, has created the Femara My Next Steps program, which may be able to help with costs. In the United States, visit the Femara website for more information.
You can also read the Breastcancer.org Paying for Your Care section for information on additional types of financial assistance and cost-lowering tips.
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Last modified on March 9, 2019 at 8:30 AM
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How does this medication work? What will it do for me?
Letrozole belongs to the group of cancer-fighting medications known as antineoplastics, and specifically to the type of antineoplastics known as nonsteroidal aromatase inhibitor.
Letrozole can be used after surgery to treat postmenopausal women with hormone receptor-positive early breast cancer, including those who have received approximately 5 years of tamoxifen therapy. Letrozole can also be used to treat postmenopausal women with advanced breast cancer. It can also be used to treat women who have gone through natural or artificially induced menopause who have breast cancer that has spread to other parts of the body and whose cancer has progressed following anti-estrogen therapy.
Letrozole fights breast cancer by inactivating an enzyme known as aromatase. This prevents the enzyme from supplying the estrogen that allows certain types of breast cancers to grow and survive.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
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What form(s) does this medication come in?
Each dark yellow, round, slightly biconvex, bevelled-edged tablet, bearing the imprint “FV” on one side and “CG” on the other, contains letrozole 2.5 mg. Nonmedicinal ingredients: cellulose compounds (microcrystalline cellulose and methylhydroxypropylcellulose), corn starch, iron oxide, lactose, magnesium stearate, polyethylene glycol, sodium starch glycolate, silicon dioxide, talc, and titanium dioxide.
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How should I use this medication?
The recommended dose of letrozole is 2.5 mg once daily. It should be taken at the same time each day and may be taken with or without food.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store the tablets in a dry place at room temperature, out of reach of children and pets.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not take letrozole if you:
- are allergic to letrozole or any ingredients of the medication
- are allergic to any other aromatase inhibitor medications (e.g., anastrozole, exemestane)
- are breast-feeding
- are pregnant
- are premenopausal
- are under 18 years of age
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
Although most of the side effects listed below don’t happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- abdominal pain
- bone fractures
- increased blood pressure
- increased cholesterol levels
- signs of infection (e.g., severe fever, chills, mouth ulcers, shortness of breath, sudden lack of energy)
- signs of depression (such as feeling sad, losing interest in things you used to enjoy, weight changes, changes in sleep habits, feelings of guilt or worthlessness, thoughts of suicide)
- signs of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
- signs of liver problems (e.g., yellow skin and eyes, nausea, loss of appetite, dark coloured urine)
- unusual vaginal bleeding
- vision changes
Stop taking the medication and seek immediate medical attention if any of the following occur:
- signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
- signs of a heart attack (e.g., tightness or feeling of heaviness in your chest or pain radiating to your arms or shoulders, neck, teeth, jaw, abdomen, or back)
- signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
- signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
- signs of a stroke (e.g., numbness or weakness in arm, leg or any part of the body, loss of coordination, vision changes, sudden headache, difficulty speaking or breathing)
- swelling of the arms, hands, feet, ankles, or other parts of the body
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.
Blood clots: Letrozole may cause an increase in the formation of blood clots in blood vessels, reducing the blood flow to organs or the extremities. In the arms or legs this is experienced as pain, swelling, warmth, or redness in the limb. In the lungs, you may experience difficulty breathing, sharp chest pain, coughing, or coughing up blood. If you experience any of these symptoms, contact your doctor immediately.
Bone mineral density: Long-term use of letrozole may decrease the density of bones, thereby increasing the risk of osteoporosis. Your doctor will order bone mineral density tests periodically while you are taking letrozole.
Cholesterol: Letrozole may increase cholesterol levels. If you have increased blood cholesterol levels or a history of increased cholesterol, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Drowsiness/dizziness: Letrozole may cause dizziness or drowsiness. If you experience either or both of these side effects, you should not drive, use machinery, or perform any other activities that require alertness.
Heart disease: This medication may increase the risk of heart attack or increased blood pressure. If you are at risk for heart disease or high blood pressure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience signs of a heart attack, such as tightness or heaviness in your chest, sudden chest pain spreading to your arms or shoulders, sweating, nausea, or anxiety, seek medical help immediately.
Kidney function: If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver function: If you have liver disease or reduced liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Premenopausal women: Letrozole should not be taken by women who have not reached menopause (either naturally or surgically), unless the potential benefits outweigh the risks.
Stroke: This medication increases the risk of a stroke or “mini-strokes” occurring as a result of blood clots forming in the blood vessels. If you experience signs of a stroke or mini-stroke, such as confusion, difficulty speaking, loss of coordination, sudden headache or vision changes, contact your doctor immediately.
Pregnancy: It is suspected that the use of letrozole during pregnancy could cause miscarriages and other serious problems. It is not intended to be taken by women who have not reached menopause.
This medication should not be taken during pregnancy unless the benefits outweigh the risks. Any woman taking this medication who may become pregnant should practice effective birth control and contact her doctor immediately if pregnancy is suspected while taking this medication.
Breast-feeding: It is not known if letrozole passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of this medication have not been established for children. Children under 18 years of age should not use this medication.
What other drugs could interact with this medication?
There may be an interaction between letrozole and any of the following:
- any estrogen-containing medications
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.
All material copyright MediResource Inc. 1996 – 2020. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/Femara
My Deep, Dark Femara Secret
Last January, my oncologist gave me a prescription for Femara because my five-year course with tamoxifen had finished. Research shows maximum benefits from hormonal treatment if tamoxifen is followed by an aromatase inhibitor like Arimidex or Femara for five years. I tried Arimidex in 2006 and wrote about how I had to stop because the side effects were so debilitating. So I initially put off taking it and then later blogged about the prescription still stuck to my fridge. Comments from many of you tried to ease my concerns and encouraged me to take it. So I agreed I would.
I need to come clean. Until I had the bone cancer scare that I wrote about last week in my blog about pain and breast cancer, I wasn’t taking Femara. I had good intentions — really I did — mostly because of concerns about metastasizing cancer, and I really wanted to follow your advice. I just kept putting it off. The thought of experiencing the side effects again that I had while on Arimidex is just such a huge drawback for me.
Well, like I said, I did start taking Femara last week. I also stopped taking it last week. Truthfully, you can’t blame me. When I discussed the side effects detailed on the pharmacy printout with Sister, it was just horrendous to think I could subject myself to those risks — they seem just as bad as cancer!
The side effects listed for Femara are things like joint pain, muscle and skeletal pain, blurry vision, chest pains, blood clots and nausea and diarrhea. Those aren’t even the serious side effects. The serious side effects are stroke and heart attack, and the warning advises you to contact your doctor if you experience jaw or arm pain or any other symptoms related to stroke or heart failure. Seriously, the pharmaceutical companies really think that this is acceptable? We are talking millions of dollars in research — plus millions more made back in profits from these drugs — and these are the things they subject us to?
In my mind, if you create a drug that can block the estrogen that feeds breast cancer, you don’t stop until you make it safe. This drug does not sound safe to me. If any woman other than a breast cancer survivor walked into her doctor’s office with any of the symptoms listed as side effects of this drug, the doctor would think she was seriously ill.
When I see my oncologist in January, I will once again have the discussion about taking Femara. I know my doctor will tell me it is important to reduce my risk of cancer spread and this drug is meant to extend my life. What kind of a life is it if I have to avoid operating heavy machinery? Oh yeah — that is one of the side effects, too.
This post first appeared on the Cancer Today website.
Data from the NSABP B-42 (NRG Oncology) trial presented Dec. 7 at the San Antonio Breast Cancer Symposium showed that five additional years of the aromatase inhibitor (AI) therapy letrozole (Femara) following an initial five years of AI-based adjuvant hormone therapy did not significantly improve survival outcomes in postmenopausal women with early-stage HR-positive breast cancer. The additional five years did improve some outcomes related to recurrence.
Data from this trial and from another small study presented Dec. 9 also indicate increased cardiovascular side effects of AI therapy. These results indicate that postmenopausal women with HR-positive breast cancer and their clinicians should use caution in making treatment decisions.
How Long for Hormone Therapy?
An important topic of discussion in HR-positive breast cancer treatment is the length of hormonal therapy that will yield maximum survival benefit to the patients.
Prior studies have shown that about half of the recurrences and about two-thirds of the deaths among patients with HR-positive early-stage breast cancer occur after the first five years from diagnosis, explains study lead author Terry Mamounas, MD, an oncologist from UF Health Cancer Center at Orlando Health. Mamounas is also on the NRG Oncology Breast Cancer Committee.
Postmenopausal women with HR-positive breast cancer are currently treated with five years of hormone therapy. Many large clinical trials have studied whether extending adjuvant hormonal therapy for longer than five years can lower the rates of breast cancer recurrence and death. Data from these studies have shown that:
- taking adjuvant tamoxifen for 10 years results in fewer recurrences than taking it for five years, and
- adjuvant AI for five years after five years of adjuvant tamoxifen results in fewer recurrences than just five years of adjuvant tamoxifen.
The NSABP B-42 trial was designed to address whether giving five years of the AI letrozole, compared with placebo, to patients who have completed five years of endocrine therapy that included an AI would improve disease-free survival (DFS), which is the time after treatment during which the patient has no signs of cancer.
The investigators randomly assigned 3,966 patients to 2.5 mg letrozole or placebo daily for five years. After a median follow-up of 6.9 years, extended letrozole therapy resulted in a 15 percent reduction in the risk of DFS. However, the risk reduction was not statistically significant—which means the findings could be attributed to chance. A DFS event included a recurrence of the original breast cancer, cancer in the opposite breast, a non-breast malignancy, or death from any cause prior to the occurrence of one of the other DFS events.
Extended letrozole therapy did not improve overall survival. However, a statistically significant improvement in breast cancer-free incidence was noted, with a 29 percent reduction in the risk of breast cancer recurrence or cancer in the opposite breast as a first event. Additionally, researchers observed a 28 percent statistically significant reduction in the cumulative risk of distant recurrence.
Cardiovascular Side Effects Are a Concern
While there was no significant increase in the overall risk of developing blood clots in the arteries in this trial, Mamounas notes that the risk became elevated for letrozole-treated patients after 2.5 years.
“Postmenopausal patients with early-stage breast cancer who approach completion of five years of therapy with an aromatase inhibitor should carefully weigh and discuss with their physician some of the above-mentioned factors before making a decision to continue or to stop therapy,” he says.
“Such an assessment needs to include patient and tumor characteristics , existing comorbidities, information on bone mineral density, as well as how well the patient tolerated the first five years of endocrine therapy,” Mamounas adds.
This seems to be the conclusion drawn by the investigators of another study presented Dec. 9, in which postmenopausal women with breast cancer who took aromatase inhibitors were found to have endothelial dysfunction, which impairs the ability of blood vessels to relax and contract. It is an early predictor of cardiovascular disease.
The study examined several components of endothelial function in 25 healthy postmenopausal women and 36 postmenopausal women taking AI therapy to treat breast cancer. Researchers found that women taking an AI had significantly higher mean systolic blood pressure and lowered elasticity of the large and small arteries.
Lead author of the study and oncologist Anne H. Blaes, MD, of the University of Minnesota in Minneapolis says, “It is important for women with breast cancer to look at the pros and cons of each medication being prescribed, as well as their risk of breast cancer recurrence.
“For example, a woman whose cancer type or stage predicts a high rate of recurrence may opt to stay on the AI for 10 years, but a woman with early-stage cancer who has other risk factors for cardiovascular disease may want to limit her time on the AI,” she notes.
Patient Advocate: Some Positive Results Offer Hope
Tracy Leduc, a breast cancer survivor who advocates for “better breast cancer research and for better treatment for patients,” says that from a patient’s perspective, the findings that extended letrozole improved breast cancer-free interval and lowered the risk for distant recurrence are positive and significant.
“As a patient, I didn’t find this study as having totally negative results,” she says.
Given that the side effects from endocrine therapies are fairly well known, she, like the researchers who presented their data, also feels that patients and their clinicians need to consider the benefits and comorbidities and decide on the amount of time the patient needs to be on AI.
Leduc, who attended SABCS for her sixth time this year, says, “The first time I attended … I had no idea what to expect, but I learned so much and I realized that by attending I was learning things that my oncologist didn’t yet know about.”