Anastrozole
ARIMIDEX
Pronunciation: an-AS-troe-zoel
“An Astro Arm-o-dex”
What it isAromatase inhibitor blocking peripheral estrogen synthesis; hormone receptor-positive breast cancer in postmenopausal women.
Why this oneUnlike steroidal exemestane, it is reversible and nonsteroidal; it lacks tamoxifen's endometrial-cancer and thrombosis liabilities.
What limits itAccelerated bone loss and arthralgia; monitor density. It is ineffective before menopause unless ovarian function is suppressed.
Anastrozole prescription history
Animated chart of estimated U.S. prescriptions per year, Oral anticancer meds (1953–2026). Anastrozole enters in 1996 (estimated).
FDA-approved for
- breast cancer (1995)
Principal riskAccelerated bone loss and arthralgia
Classes and tags
Clinical profile
Legacy pregnancy categoryMultiple / indication-, trimester- or formulation-dependent
Defining liabilityThrombotic, metabolic, hepatic, skeletal or reproductive toxicity varies by hormonal target.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Breast cancer (adjuvant early-stage, or advanced) in postmenopausal women | Postmenopausal women | 1 mg QD | 1 mg QD | 1 mg QD |
Renal No adjustment needed
Hepatic Mild-to-moderate impairment: no change; severe impairment: not studied.
Instructions
- Take with or without food
- Advanced breast cancer: continue until tumor progression
Available strengths
- tab 1 mg
Cautions
- Increased ischemic cardiovascular events in women with pre-existing ischemic heart disease
- Decreases in bone mineral density
- Increases in total cholesterol
- Embryo-fetal toxicity
Adverse reactions
- Hot flashes
- Arthralgia/arthritis
- Asthenia
- Back pain
- Nausea
- Hypertension
- Depression
- Osteoporosis / bone fractures
- Rash
Pregnancy May cause fetal harm based on animal findings and mechanism of action; embryo-fetal toxicities in rats; advise effective contraception.
Lactation No data on presence in human milk; because of tumorigenicity in animal studies, breastfeeding is not recommended.
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 1 mg | tab | 30 qd | $4.25 | offered |
Generic entry2010
Open Anastrozole in the interactive console ↗
Self-check
- When can anastrozole work before menopause?
Only with ovarian function suppression. - What skeletal effect warrants density monitoring?
Accelerated bone loss.