Femara

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. It 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 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 letrozole 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. 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.

Before taking letrozole,

• tell your doctor and pharmacist if you are allergic to letrozole, any other medications, or any of the ingredients in letrozole tablets. Ask your pharmacist for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: medications that contain estrogen such as hormone replacement therapy (HRT) and hormonal contraceptives (birth control pills, patches, rings, and injections); raloxifene (Evista); and tamoxifen (Nolvadex).
• tell your doctor if you have high cholesterol, osteoporosis (condition in which the bones are fragile and break easily), or liver disease.
• you should know that letrozole should only be taken by women who have experienced menopause and cannot become pregnant. However, if you are pregnant or breast-feeding, you should tell your doctor before you begin taking this medication. Letrozole may harm the fetus.
• you should know that letrozole may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.

Unless your doctor tells you otherwise, continue your normal diet.

Letrozole is an oral, anti-estrogen drug that is used for treating postmenopausal women with breast cancer. The growth of some breast cancers in postmenopausal women is promoted by estrogens that circulate in the blood, and the adrenal glands are the main source of these circulating estrogens. Letrozole inhibits the enzyme in the adrenal glands (aromatase) that produces the estrogens, estradiol and estrone. Letrozole was approved by the FDA in 1997.

Yes

Common Side Effects of Letrozole

You should tell your doctor if any of the following side effects are severe or don't go away:

• Bone, joint, and/or muscle pain
• Headache and nausea
• Sweating, cough
• Constipation
• Trouble breathing
• Trouble sleeping
• Weight gain
• High cholesterol
• Altered liver function tests
• Depression
• Hair loss or baldness
• Swelling of the feet, ankles, and lower legs

Serious Side Effects of Letrozole

You should stop using this medicine and call your doctor if you experience any of the following serious side effects:

• Allergic reactions, including life-threatening allergic reactions
• Bone brittleness and bone breaks
• Heart attack, stroke, blood clots, and high blood pressure
• Uterine cancer

Pregnancy

Femara is contraindicated in women of premenopausal endocrine status. The physician needs to discuss the necessity of adequate contraception with women who have the potential to become pregnant including women who are perimenopausal or who recently became postmenopausal, until their postmenopausal status is fully established.

Fatigue and Dizziness

Since fatigue and dizziness have been observed with the use of Femara and somnolence was uncommonly reported, caution is advised when driving or using machinery.

Bone Effects

Consideration should be given to monitoring bone mineral density.

• Take Femara exactly as prescribed. 
• Femara comes in tablet form and is taken once daily, with or without food.
• If this medication upsets your stomach, try taking it with food.
• Try to take Femara at the same time each day.
• If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of Femara at the same time.

Antineoplastic agent; selective aromatase inhibitor.1 2 3 6 11 13 15

Storage

Oral

25°C (may be exposed to 15–30°C).1

• Risk of dizziness, fatigue, or somnolence; use caution when driving or operating machinery.1

• Risk of osteoporosis.1 29 Life-style changes (e.g., weight-bearing exercise, abstinence from smoking, moderation of alcohol consumption) and dietary supplementation with calcium and vitamin D advised.25 29 37 Importance of BMD monitoring.1 71 73

• Risk of fetal harm if used during pregnancy.1 Necessity for perimenopausal or recently postmenopausal women to use adequate contraception until postmenopausal state is fully established.1 Contraindicated in premenopausal women.1

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.1

• Importance of informing patients of other important precautionary information.1 (See Cautions.)

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

• It is used to treat breast cancer in women after change of life.
• It may be given to you for other reasons. Talk with the doctor.

Isolated cases of Femara overdose have been reported. In these instances, the highest single dose ingested was 62.5 mg or 25 tablets. While no serious adverse reactions were reported in these cases, because of the limited data available, no firm recommendations for treatment can be made. However, emesis could be induced if the patient is alert. In general, supportive care and frequent monitoring of vital signs are also appropriate. In single-dose studies, the highest dose used was 30 mg, which was well tolerated; in multiple-dose trials, the largest dose of 10 mg was well tolerated.

Lethality was observed in mice and rats following single oral doses that were equal to or greater than 2,000 mg/kg (about 4,000 to 8,000 times the daily maximum recommended human dose on a mg/m2 basis); death was associated with reduced motor activity, ataxia and dyspnea. Lethality was observed in cats following single IV doses that were equal to or greater than 10 mg/kg (about 50 times the daily maximum recommended human dose on a mg/m2 basis); death was preceded by depressed blood pressure and arrhythmias.

Packaged in HDPE bottles with a safety screw cap.

2.5 mg tablets

      Bottles of 30 tablets...................................................................................NDC 0078-0249-15

Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

You should not use Femara if you are allergic to letrozole, or if you have:

• if you have not gone completely through menopause.

To make sure Femara is safe for you, tell your doctor if you have:

• liver disease (especially cirrhosis);

• osteoporosis, osteopenia (low bone mineral density);

• high cholesterol; or

• if you also take tamoxifen.

Although it is not likely that a postmenopausal woman would be pregnant, Femara could harm an unborn baby. Do not take this medicine if you are pregnant or may become pregnant. Use effective birth control if you are not past menopause,and tell your doctor right away if you become pregnant during treatment.

It is not known whether letrozole passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using Femara.

Letrozole is usually taken once per day, or once every other day. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You may take letrozole with or without food.

While using letrozole, you may need frequent blood tests. Your bone mineral density may also need to be checked.

Store at room temperature away from moisture and heat.

Other drugs may interact with letrozole, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.