Introduction
Anastrozole is a prescription medication used to treat breast cancer in postmenopausal women. It’s part of a class of drugs called aromatase inhibitors, which lower estrogen levels in the body. Reducing estrogen helps slow or stop the growth of certain types of breast cancer that need estrogen to grow.

Uses

Treats hormone receptor-positive breast cancer in postmenopausal women

Often used as first-line therapy or after surgery, radiation, or chemotherapy

It may be used to reduce the risk of cancer recurrence

How It Works
Anastrozole blocks the enzyme aromatase, which converts androgens into estrogen. Stopping this conversion significantly lowers estrogen levels in the body. Since some breast cancers grow in response to estrogen, reducing its presence helps to slow or shrink the tumor.

Side Effects and Precautions
Common Side Effects:

Hot flashes

Joint or muscle pain

Weakness or fatigue

Headache

Nausea

Serious (but less common) Side Effects:

Osteoporosis or bone fractures

Increased cholesterol levels

Liver function changes

Allergic reactions (rash, swelling, trouble breathing)

Precautions:

Not for use in premenopausal women

Regular bone density checks may be needed

Use caution if you have liver problems or osteoporosis

Let your doctor know about any medications you’re taking, especially hormone therapies