Anastrozole is in a class of drugs known as non-steroidal aromatase inhibitors. It decreases the amount of estrogen the body makes. This can slow or stop the growth of many types of breast cancer cells that need estrogen to grow. The length of treatment depends on the types of drugs you are taking, how well your body responds to them, and the type of cancer you have.

Precautions

Before taking anastrozole,

tell your doctor and pharmacist if you are allergic to anastrozole or any other drugs.
tell your doctor and pharmacist what 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 containing estrogen such as hormone replacement therapy (HRT) or oral contraceptives (birth control pills); and tamoxifen (Nolvadex). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
tell your doctor if you have or have ever had any medical condition, especially high cholesterol, liver disease, osteoporosis (a condition in which the bones are thin and fragile), abnormal vaginal bleeding, cancer of the uterus (womb), and blood clots.
Anastrozole should only be taken by women who have undergone menopause and cannot become pregnant. However, if you are pregnant or breastfeeding, you should tell your doctor before you begin taking this drug. You should not plan to have children while receiving chemotherapy or for a while after treatments. Use a reliable method of birth control to prevent pregnancy. Talk to your doctor for further details. Anastrozole may harm the fetus.
If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking anastrozole.

Directions

Anastrozole is usually taken once a day with or without food. Take anastrozole at around the same time every day.

Follow the directions on your prescription label carefully and ask your doctor or pharmacist to explain anything you do not understand. Take anastrozole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Continue to take anastrozole even if you feel well. Do not stop taking anastrozole without talking to your doctor.

Side Effects

Along with their useful effects all medicines can cause unwanted side effects, which usually improve as your body adjusts to the new medicine. Speak with your doctor or pharmacist if any of the following side effects continue or become troublesome.

flu-like symptoms
weakness
headache
flushing
sweating
nausea
vomiting
loss of appetite
constipation
diarrhea
heartburn
weight gain
joint, bone, or muscle pain
mood changes
depression
difficulty falling asleep or staying asleep
nervousness
dizziness
vaginal bleeding
vaginal dryness or irritation
cough
burning or tingling feeling
dry mouth
hair thinning

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately

chest pain
sore throat, fever, chills, swollen glands, and other signs of infection
difficult, painful, or urgent urination
blurred vision or vision changes
pain, swelling, redness, warmth, or tenderness in 1 leg only
pale skin
fast heartbeat
breast pain
new lumps or masses in the breasts or other parts of the body
blisters or peeling skin
rash
hives
swelling of the eyes, face, lips, tongue, throat, arms, hands, feet, ankles, or lower legs

Storage

Keep all medicines out of the reach of children.

Store in a cool, dry place, away from direct heat and light.