Anastrozole
Anastrozole is used to treat hormone receptor-positive breast cancer in postmenopausal women. It is available as Arimidex and is commonly prescribed in the oncology category.
About Anastrozole
Anastrozole is a non-steroidal aromatase inhibitor also known by the brand name Arimidex. It is primarily used to anastrozole is prescribed to treat: • Hormone receptor positive breast cancer in postmenopausal women • Various related conditions in the oncology category • Associated symptoms and complications It is an important medication that helps manage these conditions effectively. Anastrozole is available in oral tablet (1 mg) form. Healthcare providers commonly prescribe Anastrozole for conditions including Attention Deficit Hyperactivity Disorder (ADHD), Lupus Anticoagulant, and Vertigo.
Anastrozole at a Glance
- Brand names
- Arimidex
- Drug class
- Non-Steroidal Aromatase Inhibitor
- Pregnancy category
- FDA Category Category X — Anastrozole can cause fetal harm and is contraindicated in pregnancy. It is intended for postmenopausal women, but pregnancy must be excluded prior to use in any patient with reproductive potential. Effective contraception is required if perimenopausal status cannot be confirmed.
- Available forms
- Oral tablet (1 mg)
- Therapeutic categories
- Oncology, Aromatase Inhibitors, Breast Cancer
- Conditions treated
- 3 related conditions on this site
What Anastrozole Is Used For
Anastrozole is prescribed to treat:
• Hormone receptor-positive breast cancer in postmenopausal women • Various related conditions in the oncology category • Associated symptoms and complications
It is an important medication that helps manage these conditions effectively.
Dosage Quick Reference
These are general dosage guidelines for Anastrozole. Your doctor will determine the appropriate dose for your specific situation.
| Condition | Starting Dose | Maintenance Dose |
|---|---|---|
| Adjuvant treatment of HR-positive early breast cancer | 1 mg orally once daily | 1 mg once daily for 5 years (or longer per oncologist) |
| First-line treatment of HR-positive or hormone-unknown advanced breast cancer | 1 mg orally once daily | 1 mg once daily until disease progression |
| Second-line treatment after tamoxifen failure | 1 mg orally once daily | 1 mg once daily until disease progression |
Side Effects
Common side effects may include:
• Nausea or stomach upset • Headache • Dizziness or lightheadedness • Fatigue or tiredness • Mild rash or itching
Serious side effects (seek immediate medical attention):
• Severe allergic reactions (rash, hives, swelling, difficulty breathing) • Unusual bleeding or bruising • Severe stomach pain • Signs of liver problems (yellowing of skin/eyes, dark urine) • Chest pain or irregular heartbeat • Severe dizziness or fainting • Signs of serious adverse effects
See also: Drug Interactions ↓
Drug Interactions
Anastrozole has relatively few clinically significant drug interactions, but several deserve attention because of estrogen-pathway and bone-health considerations.
- Tamoxifen: Co-administration reduces anastrozole plasma concentrations by approximately 27%. The combination has not shown improved efficacy over either agent alone and should be avoided.
- Estrogen-containing therapies (oral contraceptives, hormone replacement therapy, vaginal estrogens): These directly counteract anastrozole's mechanism by restoring estrogen activity. Avoid all estrogen-containing products during therapy.
- Bisphosphonates (e.g., alendronate, zoledronic acid): Not a direct interaction, but often required adjunctively. Aromatase inhibitors accelerate bone loss; bisphosphonates or denosumab may be co-prescribed to reduce fracture risk.
- Warfarin: Anastrozole does not significantly affect warfarin pharmacokinetics in most studies, but rare INR fluctuations have been reported. Monitor INR after initiation and dose changes.
- CYP-metabolized drugs: Anastrozole has minimal effect on CYP1A2, 2C9, 2C19, 2D6, and 3A4 at therapeutic doses, so most coadministered medications do not require dose adjustment.
See also: Questions to Ask Your Doctor ↓
Key Considerations
Known drug interactions
Anastrozole has documented interactions with other medications, supplements, and certain foods. Review the Drug Interactions section below and tell your healthcare provider about every medication you take, including over-the-counter products. Jump to section →
Additional Information
What is Anastrozole?
Anastrozole (generic name: Anastrozole) is a medication primarily used to treat hormone receptor-positive breast cancer in postmenopausal women. It is marketed under the brand name(s) Arimidex and belongs to the Oncology category of medications.
How Does Anastrozole Work?
Anastrozole works through several mechanisms to provide therapeutic benefits:
- Acts on specific receptors or pathways in the body
- Modulates biological processes related to the treated condition
- Provides symptom relief and improves quality of life
- Helps manage the underlying condition effectively
- Works best when combined with appropriate lifestyle modifications
The medication is designed to target the specific pathways involved in hormone receptor-positive breast cancer in postmenopausal women, making it an effective treatment option.
Common Uses
Primary Indications
Anastrozole is commonly prescribed for:
- Hormone receptor-positive breast cancer in postmenopausal women: The main indication for this medication
- Related Conditions: Associated symptoms and complications
- Prevention: May help prevent progression of certain conditions
- Symptom Management: Reduces discomfort and improves daily function
Additional Uses
In some cases, Anastrozole may also be prescribed for:
- Off-label uses as determined by your healthcare provider
- Combination therapy with other medications
- Long-term management of chronic conditions
- Short-term treatment of acute symptoms
Dosage and Administration
Anastrozole dosing varies based on the specific condition being treated and individual patient factors.
Typical Dosing:
- Starting dose is typically determined by your healthcare provider
- May be adjusted based on response and tolerability
- Can be taken with or without food (follow specific instructions)
- Usually taken once or twice daily
Administration Tips:
- Take at the same time(s) each day for best results
- Swallow tablets/capsules whole unless instructed otherwise
- Don't skip doses
- Complete full course of treatment as prescribed
- Follow your doctor's specific instructions carefully
Important Safety Information
Who Should Not Take Anastrozole?
Do not take Anastrozole if you:
- Are allergic to Anastrozole or any ingredients
- Have certain medical conditions (discuss with your doctor)
- Are taking medications that interact with Anastrozole
- Have severe liver or kidney disease (without dose adjustment)
Drug Interactions
Inform your doctor about all medications you take, including:
- Prescription medications
- Over-the-counter drugs
- Vitamins and supplements
- Herbal products
Some medications may interact with Anastrozole, affecting its efficacy or increasing side effect risk.
Pregnancy and Breastfeeding
Pregnancy:
- Discuss risks and benefits with your doctor if pregnant or planning pregnancy
- May require special monitoring or dose adjustments
- Some medications should be avoided during pregnancy
Breastfeeding:
- Consult your doctor about safety while breastfeeding
- May pass into breast milk
- Benefits and risks should be carefully considered
Monitoring and Follow-Up
While taking Anastrozole, your doctor may monitor:
- Effectiveness of treatment (symptom improvement)
- Side effects or adverse reactions
- Laboratory values if applicable
- Blood pressure, heart rate, or other vital signs as appropriate
- Overall response to therapy
Regular follow-up appointments are important to ensure the medication is working properly and to make any necessary adjustments.
Managing Side Effects
Most side effects are mild and improve with time. Here are strategies for common side effects:
Gastrointestinal Upset
- Take with food if allowed
- Stay well hydrated
- Eat smaller, more frequent meals
- Report persistent nausea or vomiting
Dizziness
- Rise slowly from sitting or lying positions
- Avoid sudden movements
- Stay hydrated
- Avoid alcohol
- Report severe or persistent dizziness
Fatigue
- Get adequate rest
- Maintain regular sleep schedule
- Exercise as tolerated
- Report excessive tiredness that interferes with daily activities
Lifestyle Considerations
To maximize the benefits of Anastrozole:
- Follow a healthy, balanced diet
- Exercise regularly as recommended by your doctor
- Maintain a healthy weight
- Avoid alcohol or limit consumption
- Don't smoke
- Manage stress through relaxation techniques
- Get adequate sleep
- Stay well hydrated
- Keep all follow-up appointments
- Take medication consistently as prescribed
When to Contact Your Doctor
Seek immediate medical attention if you experience:
- Signs of severe allergic reaction (difficulty breathing, severe rash, swelling)
- Chest pain or rapid heartbeat
- Severe dizziness or fainting
- Unusual bleeding or bruising
- Signs of liver problems (yellowing of skin/eyes, dark urine, severe fatigue)
- Severe stomach pain
- Any symptoms that concern you
Contact your doctor for non-emergency issues:
- Mild to moderate side effects that persist
- Questions about your medication
- Concerns about effectiveness
- New medications prescribed by another doctor
- Scheduled surgery or dental procedures
- Planning pregnancy
Storage
Store Anastrozole at room temperature (68-77°F or 20-25°C) away from light, heat, and moisture. Keep in original container. Keep out of reach of children and pets. Do not use past expiration date.
Important Reminders
- Take exactly as prescribed by your doctor
- Don't stop suddenly without medical advice
- Keep all follow-up appointments
- Report any unusual symptoms
- Don't share medication with others
- Store safely away from children
- Check expiration dates
- Ask your pharmacist if you have questions
Clinical Benefits
When used appropriately, Anastrozole provides several benefits:
- Effective management of hormone receptor-positive breast cancer in postmenopausal women
- Improvement in quality of life
- Reduction in symptoms
- Prevention of complications
- Generally well-tolerated when used as directed
- Backed by clinical research and extensive use
Disclaimer: This information is for educational purposes only and is not intended to replace professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified healthcare provider with any questions about a medical condition or medication.
Frequently Asked Questions
Questions to Ask Your Doctor About Anastrozole
Consider discussing these topics at your next appointment:
- When should I have my first DEXA bone density scan, and how often will it be repeated?
- What can I do to manage joint pain or stiffness if it develops?
- How will you monitor for response and recurrence while I am on anastrozole?
- Are there any vaginal symptoms or sexual side effects I should report — and what can be done about them?
- Should I consider an extended course beyond 5 years given my specific tumor profile?
Medical Disclaimer: This information is for educational purposes only and should not be considered medical advice. Always consult with your healthcare provider before starting, stopping, or changing any medication. Your doctor can provide personalized recommendations based on your specific health condition and medical history.