LETROZOLE (Systemic)

Some commonly used brand names are:

In the U.S.?

• Femara

In Canada?

• Femara

Category

• Antineoplastic

Description

Letrozole (LET-roe-zole)isused to treat certain types of breast cancer in women. Female hormones thatoccur naturally in the body can increase the growth of some breast cancers.Letrozole works by decreasing the amounts of these hormones in the body. Thismedicine is meant to be used only by women who have already stopped menstruating.

This medicine is available only with your doctor's prescription, in thefollowing dosage form:

Oral
• Tablets (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For letrozole, the followingshould be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to letrozole. Also tell your health care professional ifyou are allergic to any other substances, such as foods, preservatives, ordyes.

Pregnancy?This medicine is meant to be used only by women whoare no longer able to have children. If this medicine is taken by a pregnantwoman for any reason it may cause harm to, and possibly even death of, thefetus.

Older adults?This medicine has been tested and has not been shownto cause different effects in older women than in younger adults.

Other medical problems?The presence of other medical problems may affectthe use of letrozole. Make sure you tell your doctor if you have any othermedical problems, especially:

• Cirrhosis or
• Kidney disease or
• Liver disease or
• Severe liver disease?Problems are not likely to occur in peoplewith mild kidney or liver disease. However, the dose of letrozole should bereduced in patients with cirrhosis and severe liver disease.

Proper Use of This Medicine

Take this medicine only as directed by your doctor. Do not take moreof it, and do not take it more often than your doctor ordered.

Dosing?The dose of letrozole may be different fordifferent patients. Follow your doctor's orders or thedirections on the label. The following information includes only theaverage dose of letrozole. If your dose is different,do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets):
  • For breast cancer:
    • Adults?One 2.5-milligram tablet a day.

Missed dose?If you miss a dose of this medicine, take it assoon as you remember. However, if you do not remember until the next day,skip the missed dose and go back to your regular dosing schedule. Do not doublethe next day's dose.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

It isvery important that your doctor check your progress at regular visits to makesure that the medicine is working properly and does not cause unwanted effects.

This medicine may cause you to become dizzy or drowsy; use caution if youare driving an automobile or using machinery.

Side Effects of This Medicine

Along with its needed effects, a medicine maycause some unwanted effects. Although not all of these side effects may occur,if they do occur they may need medical attention.

The following side effects may be caused byblood clots, which could lead to a heart attack or a stroke. Stop taking this medicine and get emergency help immediately if anyof the following side effects occur:

More common

Shortness of breath

Less common

Chest pain

Rare

Continuing or severe nervousness; cough; dizziness or lightheadedness; fainting; fast heartbeat; heart attack; increased sweating; nausea; pain in chest, groin, or legs, especiallythe calves; severe, sudden headache; slurred speech; severe and sudden, unexplainedshortness of breath; sudden loss of coordination; sudden, severe weakness or numbness in arm or leg; vision changes

Also, check with your doctoras soon as possible if any of the following side effects occur:

Less common

Bone fracture; breast pain; chills, fever, or flu-like symptoms; mental depression; swelling of feet or lower legs

Rare

Vaginal bleeding

Other side effects may occurthat usually do not need medical attention. These side effects may go awayduring treatment as your body adjusts to the medicine. However, check withyour doctor if any of the following side effects continue or are bothersome:

More common

Back pain; bone pain; hot flashes (sudden sweating and feeling of warmth); joint pain; muscle pain

Less common

Anxiety; confusion; constipation; diarrhea; dry mouth; headache; increasedthirst and urination; loss of appetite or weightloss; metallic taste; skinrash or itching; sleepiness; spinning or whirling sensation causing loss of balance; stomach pain or upset; trouble sleeping; unusual tiredness; vomiting; weakness; weight gain

Incidence not known

Blurred vision

Letrozole sometimes causes a loss of hair.

Other side effects not listed above may also occur in some patients. Ifyou notice any other effects, check with your doctor.