abiraterone vs anastrozole
Side-by-side comparison of abiraterone and anastrozole Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zytiga
Arimidex
Abiraterone (Zytiga) is a medicine used with prednisone to treat prostate cancer that has spread. It works by lowering the amount of androgen your body makes.
Anastrozole is a medicine used to treat breast cancer in women after menopause. It lowers estrogen levels in the body, which can help stop the growth of cancer cells.
Abiraterone is used to treat prostate cancer that has spread to other parts of the body. It is for cancers that are castration-resistant, meaning they no longer respond to hormone therapy alone. It is also used for high-risk castration-sensitive prostate cancer. You will take this medicine with prednisone.
Anastrozole is used to treat breast cancer in women who have gone through menopause. It can be used as the first treatment for advanced breast cancer, or after other treatments like tamoxifen have stopped working. It is also used to lower the risk of breast cancer returning after surgery.
Abiraterone blocks an enzyme called CYP17, which your body needs to make androgens. Androgens can help prostate cancer grow. By blocking this enzyme, abiraterone lowers androgen levels and slows cancer growth.
Anastrozole belongs to a class of drugs called aromatase inhibitors. It works by blocking an enzyme called aromatase, which the body uses to make estrogen. By lowering estrogen levels, anastrozole can slow or stop the growth of breast cancer cells that need estrogen to grow.
- • Feeling tired
- • Joint pain
- • High blood pressure
- • Feeling sick to your stomach
- • Swelling
- • Hot flashes
- • Weakness or fatigue
- • Arthritis
- • Pain
- • Joint pain
- Death 1,390
- Feeling tired 1,022
- Hot flash 678
- Weakness 562
- Worsening of disease 561
- Tiredness 3,255
- Joint pain 3,157
- Feeling sick to your stomach 2,647
- Hair loss 2,536
- Loose stools 2,266
Abiraterone can cause problems with mineralocorticoid excess, like high blood pressure, low potassium, and fluid retention. If you have heart problems, your doctor will monitor you closely. This medicine can also cause liver problems, which can be severe. Your doctor will check your liver function regularly. Do not take abiraterone with radium Ra 223 dichloride. Abiraterone can harm an unborn baby, so men should use effective birth control if their partner can get pregnant.
Anastrozole may cause heart problems in women who already have heart disease. It can also weaken your bones, so your doctor may want to check your bone density. This medicine can harm an unborn baby, so use birth control while taking it and for 3 weeks after your last dose.
Abiraterone can cause harm to an unborn baby. Men who are taking abiraterone should use effective birth control during treatment and for 3 weeks after the last dose if their partner is able to get pregnant. It is not known if abiraterone passes into breast milk.
Anastrozole can cause harm to an unborn baby. You should not take anastrozole if you are pregnant. Use effective birth control while taking anastrozole and for at least 3 weeks after your last dose. Do not breastfeed while taking anastrozole and for 2 weeks after the last dose.
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How to Read This abiraterone vs anastrozole Comparison
abiraterone is classified in the CYP17 Inhibitor drug class, while anastrozole sits within the Aromatase Inhibitor class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, abiraterone has 4,213 submissions while anastrozole has 13,861. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between abiraterone and anastrozole — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.