Abiraterone for Prostate Cancer (Zytiga)
Comprehensive guide to abiraterone acetate (Zytiga), a key hormone therapy for advanced prostate cancer, including usage, benefits, and side effects.
About Abiraterone tablets
Abiraterone acetate (Zytiga®) is a targeted hormone therapy used to treat advanced prostate cancer, particularly metastatic castration-resistant prostate cancer (mCRPC). It works by inhibiting the production of androgens (male hormones like testosterone) at multiple sites in the body, including the testes, adrenal glands, and prostate tumor itself. Prostate cancer cells rely on androgens to grow, so reducing these hormones slows cancer progression.
Approved by the FDA in 2011 initially for post-chemotherapy mCRPC in combination with prednisone, its indication expanded in 2012 to include use before chemotherapy. Abiraterone is taken orally once daily and has shown significant survival benefits in clinical trials, extending median survival by 3.9 to 4.6 months compared to placebo.
Key facts about abiraterone tablets
- Abiraterone is a
hormone therapy drug
specifically for prostate cancer that has spread (advanced or metastatic prostate cancer). - It blocks the enzyme
CYP17
, preventing androgen synthesis at three sources: testes, adrenal glands, and tumor tissue. - Taken as
tablets once a day
with prednisone (a steroid) to manage side effects and enhance efficacy. - Not suitable for women, especially pregnant ones, due to risk of fetal harm (Pregnancy Category X).
- Commonly used in
castration-resistant prostate cancer (CRPC)
, where cancer progresses despite low testosterone levels.
About prostate cancer and the need for abiraterone
Prostate cancer is one of the most common cancers in men. It often responds initially to treatments that lower testosterone, such as surgery or medications. However, in advanced stages, it becomes castration-resistant (CRPC), meaning it grows despite castrate testosterone levels (<50 ng/dL). Metastatic CRPC spreads to bones, lymph nodes, or other organs and is life-threatening.
Traditional hormone therapies target testicular testosterone, but CRPC produces androgens elsewhere. Abiraterone addresses this by comprehensively blocking androgen biosynthesis, offering a new treatment avenue post- or pre-chemotherapy like docetaxel.
How abiraterone works to treat prostate cancer
Abiraterone acetate is a selective inhibitor of the cytochrome P450 17A1 (CYP17) enzyme, crucial for androgen production. This enzyme converts precursors into testosterone and dihydrotestosterone (DHT) in the testes (90% of androgens), adrenal glands (10%), and prostate cancer cells themselves.
By inhibiting CYP17, abiraterone drastically reduces systemic and intratumoral androgen levels, starving cancer cells. Unlike older therapies (e.g., LHRH agonists), it targets extra-gonadal sources. It’s always combined with low-dose prednisone (5 mg twice daily) to counteract the mineralocorticoid excess caused by enzyme blockade, which elevates ACTH and thus aldosterone.
Clinical studies showed PSA declines in 50-70% of patients: 51% achieved ≥50% drop, 68% ≥30%, and 15% ≥90%.
Common questions about abiraterone tablets
How do I take abiraterone?
Take
1 gram (four 250 mg tablets)
once daily on an empty stomach—at least 1 hour before or 2 hours after food—with a full glass of water. Swallow whole; do not crush or chew. Take prednisone 5 mg twice daily as directed.Miss a dose? Skip it and resume the next day—do not double up. Continue until disease progression or unacceptable toxicity.
Choosing the right dose of abiraterone
Standard dose: 1000 mg once daily + prednisone 10 mg/day (5 mg BID). Dose reductions to 750 mg or 500 mg if grade 3/4 toxicities occur (e.g., hypertension, hypokalemia). Monitor blood pressure, potassium, and liver function every two weeks initially, then monthly.
| Dose Level | Abiraterone | Prednisone | Notes |
|---|---|---|---|
| Starting | 1000 mg QD | 5 mg BID | On empty stomach |
| First Reduction | 750 mg QD | 5 mg BID | For moderate toxicity |
| Second Reduction | 500 mg QD | 5 mg BID | Do not reduce further |
Getting the most from your abiraterone treatment
- Avoid food with doses—fatty meals increase absorption 10-fold, risking overdose.
- Monitor for side effects: monthly blood tests for liver enzymes (ALT/AST), potassium, and blood pressure.
- Report symptoms like fatigue, swelling, or dark urine immediately.
- Stay hydrated; maintain a heart-healthy diet low in salt to manage fluid retention.
- Do not stop suddenly without doctor advice—taper prednisone if discontinuing.
Possible side effects of abiraterone tablets
Abiraterone is generally well-tolerated but causes side effects due to androgen suppression and mineralocorticoid excess. Most are manageable with monitoring and prednisone.
Common side effects
- Fluid retention/edema: Up to 30% of patients; swelling in legs/ankles.
- High blood pressure (hypertension): Monitor weekly initially.
- Low potassium (hypokalemia): Causes muscle weakness, cramps.
- Liver function abnormalities: Elevated ALT/AST in 10-15%; usually reversible.
- Fatigue, joint pain, hot flushes.
Serious side effects
- Adrenocortical insufficiency: Rare; symptoms include nausea, low BP.
- Cardiovascular events: Heart failure, arrhythmias in those with history.
- Severe liver injury: Discontinue if ALT >20x ULN.
- QT prolongation: Avoid with other QT-prolonging drugs.
In phase 3 trials (N=1195), serious adverse events occurred in 42% (abiraterone) vs. 38% (placebo).
Drug interactions with abiraterone
Abiraterone inhibits
CYP2D6
(moderate) and is metabolized byCYP3A4
. Key interactions:| Drug Class | Examples | Advice |
|---|---|---|
| CYP2D6 Substrates (narrow index) | Dextromethorphan, thioridazine | Avoid or reduce dose |
| CYP3A4 Inhibitors | Ketoconazole, itraconazole | Avoid; increases abiraterone levels |
| CYP3A4 Inducers | Rifampin, phenytoin | Avoid; decreases efficacy |
| Other | Spironolactone | Avoid; may stimulate cancer |
Other medicines, food, alcohol, and abiraterone
- Food: No food 2 hours before/1 hour after—high-fat meals boost exposure.
- Alcohol: Limit; may stress liver.
- Herbals: Avoid St. John’s wort (CYP3A4 inducer).
- Inform doctor of all meds, including OTC.
Pregnancy, breastfeeding, and fertility while taking abiraterone
Contraindicated in pregnancy (Category X)—causes fetal harm. Not for women. Men: use condom if partner could become pregnant; abiraterone passes in semen.
Fertility: May impair spermatogenesis; discuss sperm banking. Breastfeeding: Not applicable.
Monitoring while on abiraterone
- Blood tests: PSA, testosterone, liver (ALT/AST), potassium, renal function—every 2 weeks x3, then monthly.
- BP and weight: Weekly initially.
- Imaging: Bone scan/CT every 3-6 months or as needed.
Common concerns about abiraterone
| Concern | Details |
|---|---|
| Will it cure my cancer? | No, but extends survival and delays progression. |
| How long to work? | PSA drop in weeks; radiographic response in months. |
| What if side effects? | Dose adjust or pause; most resolve. |
Frequently asked questions about abiraterone
Will my sex life be affected by abiraterone?
Yes, androgen suppression causes low libido, erectile dysfunction in most men. Not primarily for symptom relief.
Can abiraterone affect my driving or work?
Unlikely, but fatigue or low potassium may impair. Avoid if dizzy.
Should I avoid any particular foods or drinks?
Yes, no food near doses; low-salt diet for BP.
Can I have vaccinations while on abiraterone?
Live vaccines no; killed OK. Check with doctor.
How long will I take abiraterone for?
Until progression, intolerance, or doctor advises stop. Median duration ~8 months in trials.
References
- ZYTIGA™ (Abiraterone Acetate) Receives FDA Approval For Treatment of Metastatic Prostate Cancer — Janssen (Johnson & Johnson). 2011-04-28. https://www.jnj.com/media-center/press-releases/zytiga-abiraterone-acetate-receives-fda-approval-for-treatment-of-metastatic-prostate-cancer-after-priority-review
- Abiraterone (Zytiga), a Novel Agent for the Management of Castration-Resistant Prostate Cancer — National Center for Biotechnology Information (PMC). 2013-04-01. https://pmc.ncbi.nlm.nih.gov/articles/PMC3628169/
- Abiraterone — Prostate Cancer UK. Accessed 2026. https://prostatecanceruk.org/prostate-information-and-support/treatments/abiraterone
- Abiraterone (Zytiga) — Cancer Research UK. Accessed 2026. https://www.cancerresearchuk.org/about-cancer/treatment/drugs/abiraterone
- A new way to treat prostate cancer: The story of abiraterone — The Institute of Cancer Research (ICR). Accessed 2026. https://www.icr.ac.uk/about-us/icr-news/detail/a-new-way-to-treat-prostate-cancer-the-story-of-abiraterone
- Abiraterone acetate (Zytiga®) — Macmillan Cancer Support. Accessed 2026. https://www.macmillan.org.uk/cancer-information-and-support/treatments-and-drugs/abiraterone
- Abiraterone: MedlinePlus Drug Information — U.S. National Library of Medicine (MedlinePlus). Accessed 2026. https://medlineplus.gov/druginfo/meds/a611046.html
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