(Treatment for cancer)
The following prescribing information is based on official labeling in effect July 2003.
Trade Mark: Femara
What is letrozole?
¡ò Letrozole blocks the use of estrogen by certain types of breast cancer that require estrogen to grow.
¡ò Letrozole is used to treat breast cancer.
¡ò Letrozole may also be used for purposes other than those listed in this medication guide.
Femara ? (letrozole tablets) for oral administration contains 2.5 mg of letrozole, a nonsteroidal aromatase inhibitor (inhibitor of estrogen synthesis). It is chemically described as 4,4'-(1H-1,2,4-Triazol-1-ylmethylene)dibenzonitrile, and its structural formula is
Letrozole is a white to yellowish crystalline powder, practically odorless, freely soluble in dichloromethane, slightly soluble in ethanol, and practically insoluble in water. It has a molecular weight of 285.31, empirical formula C 17 H 11 N 5 , and a melting range of 184¡ãC-185¡ãC.
Femara ? (letrozole tablets) is available as 2.5 mg tablets for oral administration.
Inactive Ingredients: Colloidal silicon dioxide, ferric oxide, hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, maize starch, microcrystalline cellulose, polyethylene glycol, sodium starch glycolate, talc, and titanium dioxide.
What are the possible side effects of letrozole?
¡ò Stop taking letrozole and seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives) to letrozole. shortness of breath or coughing;
¡ò Other, less serious side effects may be more likely to occur. Continue to take letrozole and talk to your doctor if you experience
increased blood pressure;
muscle or joint pain;
swelling or water retention;
nausea and vomiting;
diarrhea or constipation;
loss of appetite;
weight gain; or
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.
What other drugs will affect letrozole?
There are no known interactions between letrozole and other medications. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines during treatment with letrozole.