Anastrozole (anastrozole)
Multiple manufacturers (generic); original brand: Arimidex by AstraZeneca · Non-Steroidal Aromatase Inhibitor
What is Anastrozole? Anastrozole (brand: Arimidex) is a non-steroidal aromatase inhibitor by AstraZeneca used as first-line adjuvant therapy for postmenopausal women with hormone receptor-positive early breast cancer, and for advanced breast cancer after tamoxifen.
About Anastrozole
| Brand Name | Anastrozole |
| Generic / INN | anastrozole |
| Drug Class | Non-Steroidal Aromatase Inhibitor |
| Manufacturer | Multiple manufacturers (generic); original brand: Arimidex by AstraZeneca |
| Administration | Oral tablet |
| FDA Approval | 1995 |
FDA-Approved Uses for Anastrozole
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Early breast cancer — adjuvant treatment of postmenopausal women with HR-positive early breast cancer
- Early breast cancer — first-line adjuvant treatment after tamoxifen for 5 years in postmenopausal women with HR-positive early breast cancer
- Advanced breast cancer — first-line treatment of postmenopausal women with HR-positive advanced breast cancer
- Advanced breast cancer — treatment of postmenopausal women with HR-positive advanced breast cancer after tamoxifen failure
How Does Anastrozole Work?
Anastrozole reversibly inhibits the aromatase enzyme (CYP19), blocking conversion of androgens to estrogens in peripheral tissues (fat, muscle, liver). In postmenopausal women (the primary source of estrogens after menopause), this reduces circulating estradiol levels by >80%, depriving hormone receptor-positive breast cancer of its growth signal.
Dosage & Administration
1 mg orally once daily, with or without food. Adjuvant use: typically for 5 years (or up to 10 years in extended adjuvant settings per clinical guidelines). Used in postmenopausal women.
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Bone mineral density loss — assess bone health before and during treatment; calcium/vitamin D and bisphosphonates may be required. Not for use in premenopausal women without ovarian suppression. Embryo-fetal toxicity (teratogenic). Elevated cholesterol. Hepatotoxicity (rare).
- Bone mineral density loss / fractures
- Embryo-fetal toxicity
- Ischemic cardiovascular events
- Hepatotoxicity (rare)
Common Side Effects
- Hot flashes
- Arthralgia / joint stiffness
- Fatigue
- Mood changes
- Osteoporosis/bone loss
- Nausea
- Headache
- Elevated cholesterol
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Store at room temperature 20°C to 25°C (68°F to 77°F).
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Anastrozole is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Anastrozole. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Anastrozole
Anastrozole (Arimidex) is a non-steroidal aromatase inhibitor that reduces estrogen production in postmenopausal women. It is used as first-line adjuvant therapy for HR-positive early breast cancer and for advanced breast cancer.
Both are aromatase inhibitors. Anastrozole is non-steroidal and reversible (Type II). Exemestane is steroidal and irreversibly inactivates aromatase (Type I). Clinical outcomes are broadly similar; choice depends on tolerability and patient/physician preference.
Yes. Generic anastrozole 1 mg tablets are among the most widely available oral oncology generics. The original brand Arimidex is manufactured by AstraZeneca.
Standard adjuvant therapy is 5 years. Extended adjuvant therapy (up to 10 years total with tamoxifen and/or an AI) may be recommended for high-risk patients based on clinical guidelines.
Related Medications & Conditions
Related Medications
Exemestane · Letrozole (Femara) · Tamoxifen · Verzenio (abemaciclib) · Ibrance (palbociclib)
Related Conditions
HR+ breast cancer · Early breast cancer adjuvant · Metastatic breast cancer · Postmenopausal breast cancer