Anastrozole for Breast Cancer: How It Works and What to Expect
Anastrozole is an aromatase inhibitor that reduces estrogen in postmenopausal women with hormone-receptor-positive breast cancer. Learn how it works, side effects, and treatment timelines.
What Anastrozole Does
Anastrozole is an aromatase inhibitor, a type of hormone therapy used to treat hormone-receptor-positive breast cancer in postmenopausal women. It works by blocking aromatase, an enzyme that converts other hormones into estrogen in the body.
By lowering estrogen levels, anastrozole slows or stops the growth of estrogen-dependent breast cancer cells.
How You Take It
Anastrozole comes as a 1 mg tablet taken by mouth once daily. You take it at the same time each day, with or without food.
Treatment typically continues for 5 to 10 years, depending on your individual situation and what your oncologist recommends.
Common Side Effects
Most people tolerate anastrozole well, but side effects do occur. The most common include:
- Hot flashes
- Joint and muscle pain (arthralgias and myalgias)
- Fatigue
- Headache
- Nausea
- Vaginal dryness
Bone density loss is a concern with longer-term use. Your doctor may recommend bone density screening and calcium or vitamin D supplementation.
What to Tell Your Doctor
Before starting anastrozole, tell your doctor if you have:
- Osteoporosis or low bone density
- Liver disease
- High cholesterol
- Heart disease
- Allergies to anastrozole or any ingredients
Also mention all other medications and supplements you take, as anastrozole can interact with certain drugs.
Important Notes
Anastrozole is not for premenopausal women. If you are still menstruating or may become pregnant, this medication is not appropriate for you.
Never stop taking anastrozole without talking to your oncologist first, even if you experience side effects. Your doctor can help manage symptoms or adjust your treatment plan.