abiraterone vs tamoxifen
Side-by-side comparison of abiraterone and tamoxifen Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zytiga
Nolvadex
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.
Tamoxifen (Soltamox) is a medicine that can treat breast cancer. It can also lower the chance of getting breast cancer in some people.
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.
This medicine is used to treat breast cancer that has spread in adults. It can also be used after surgery to help prevent breast cancer from returning in adults. Tamoxifen can also lower the risk of invasive breast cancer after breast surgery and radiation for ductal carcinoma in situ (DCIS). Finally, it can lower the chance of getting breast cancer in women who are at high risk.
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.
Tamoxifen belongs to a class of drugs called Selective Estrogen Receptor Modulators (SERMs). It works by blocking the effects of estrogen in breast tissue. This can help to stop the growth of breast cancer cells.
- • Feeling tired
- • Joint pain
- • High blood pressure
- • Feeling sick to your stomach
- • Swelling
- • Hot flashes
- • Mood changes
- • Vaginal discharge
- • Vaginal bleeding
- • Nausea
- Death 1,390
- Feeling tired 1,022
- Hot flash 678
- Weakness 562
- Worsening of disease 561
- Tiredness 391
- Feeling sick to your stomach 337
- Loose stools 274
- Joint pain 271
- Cancer getting worse 249
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.
Tamoxifen can cause serious and life-threatening problems, including cancer of the uterus, stroke, and blood clots in the lungs. Some cases have been fatal. Talk to your doctor about the risks and benefits of taking tamoxifen, especially if you are at high risk for breast cancer or have DCIS. For most people already diagnosed with breast cancer, the benefits of tamoxifen outweigh the risks.
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.
Tamoxifen can harm an unborn baby. If you are a woman who could become pregnant, your doctor will perform a pregnancy test before you start taking tamoxifen. Use effective birth control while taking tamoxifen and for several months after your last dose. Do not breastfeed while taking this medicine.
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How to Read This abiraterone vs tamoxifen Comparison
abiraterone is classified in the CYP17 Inhibitor drug class, while tamoxifen sits within the Selective Estrogen Receptor Modulator (SERM) 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 tamoxifen has 1,522. 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 tamoxifen — 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.