abiraterone vs conjugated estrogens
Side-by-side comparison of abiraterone and conjugated estrogens Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Zytiga
Premarin
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.
Premarin Intravenous is an injectable medicine that contains estrogen hormones. It is used to quickly raise estrogen levels for a short time.
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.
Premarin Intravenous treats unusual bleeding from the uterus when it's caused by hormone problems and not by other health issues. It is only for short-term use. It helps to quickly and temporarily increase your estrogen levels.
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.
Premarin Intravenous contains estrogen hormones. These hormones help to control the menstrual cycle. By providing estrogen, it can help stop abnormal uterine bleeding caused by a hormone imbalance.
- • Feeling tired
- • Joint pain
- • High blood pressure
- • Feeling sick to your stomach
- • Swelling
- • Nausea
- • Headache
- • Dizziness
- • Joint pain
- • Anxiety
- Death 1,390
- Feeling tired 1,022
- Hot flash 678
- Weakness 562
- Worsening of disease 561
- Breast cancer 9,622
- Breast cancer in women 8,862
- The medicine did not work 3,281
- Feeling sick to your stomach 2,360
- Head pain 2,290
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.
Estrogen-alone therapy can increase the risk of uterine cancer, stroke, blood clots, and dementia. Estrogen with progestin can increase the risk of blood clots, stroke, heart attack, and dementia. Use the lowest dose for the shortest time needed.
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.
You should not use Premarin Intravenous if you are pregnant or think you might be pregnant. Talk to your doctor if you are breastfeeding before using this medicine.
How to Read This abiraterone vs conjugated estrogens Comparison
abiraterone is classified in the CYP17 Inhibitor drug class, while conjugated estrogens sits within the Conjugated Estrogen 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 conjugated estrogens has 26,415. 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 conjugated estrogens — 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.