LETROZOLE blocks the formation of the hormone estrogen. Some types of breast cancer need estrogen, and letrozole stops tumor growth by decreasing estrogen levels. Letrozole is for the treatment of breast cancer in postmenopausal women only.

They need to know if you have any of these conditions:

• liver disease
• osteoporosis
• an unusual or allergic reaction to letrozole, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

Take letrozole tablets by mouth at the same time each day. Swallow the tablets with a drink of water. Do not take your medicine more often than directed. Do not stop taking except on your prescriber's advice.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses. If you vomit after taking a dose, call your prescriber or health care professional for advice.

• androstenedione
• any medicine containing estrogens (This may include some herbal products and some birth control pills)
• DHEA

Tell your prescriber or health care professional about all other medicines you are taking, including nonprescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.

Visit your prescriber or health care professional for regular checks on your progress. Let your prescriber or health care professional know about any unusual vaginal bleeding.

Do not treat yourself for diarrhea, nausea, vomiting or other side effects. Ask your prescriber or health care professional for advice.

Side effects that you should report to your prescriber or health care professional as soon as possible:

• difficulty breathing
• chest pain
• leg pain or swelling
• skin rash

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):

• back or bone pain
• cough, or throat infection
• diarrhea or constipation
• dizziness
• headache
• hair loss
• hot flashes
• loss of appetite
• nausea, vomiting
• stomach pain or upset stomach
• sweating
• weakness or tiredness
• weight gain

This list may not describe all possible side effects.

Keep out of the reach of children in a container that small children cannot open.

Store between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medicine after the expiration date.