Abiraterone is a medication used to treat advanced prostate cancer. It works by blocking the production of male hormones (androgens) that fuel prostate cancer growth, and it’s prescribed for both metastatic castration-sensitive and metastatic castration-resistant prostate cancer. The FDA first approved it in 2011 for castration-resistant disease and expanded its approval in 2018 to include high-risk castration-sensitive prostate cancer.
How Abiraterone Works
Prostate cancer cells rely on testosterone and other androgens to grow and multiply. Standard hormone therapy works by lowering testosterone produced in the testicles, but the adrenal glands and even tumor cells themselves can still produce small amounts of androgens. Abiraterone shuts down a key enzyme involved in androgen production throughout the body, not just in the testicles. By cutting off this fuel supply more completely, it slows or stops cancer growth even when standard hormone therapy has stopped working.
Because this enzyme is also involved in making cortisol (a hormone your body needs to function), blocking it creates a domino effect. Steroid precursors that can no longer be converted into cortisol or androgens get redirected toward producing mineralocorticoids instead. These are hormones that cause your body to hold onto sodium and lose potassium, which can raise blood pressure and cause fluid retention. This is why abiraterone is always prescribed alongside a low-dose corticosteroid: the corticosteroid replaces the missing cortisol and helps prevent this hormonal imbalance.
Who Gets Prescribed Abiraterone
Abiraterone is used in two main settings. The first is metastatic castration-resistant prostate cancer, meaning the cancer has spread and is growing despite testosterone being at very low levels from prior hormone therapy. This was abiraterone’s original approval. The second is metastatic high-risk castration-sensitive prostate cancer, where the cancer has spread but still responds to standard hormone suppression. Adding abiraterone early in this setting, rather than waiting for resistance to develop, has shown meaningful survival benefits.
Current treatment guidelines from the National Comprehensive Cancer Network consider abiraterone one of four generally interchangeable androgen receptor pathway inhibitors for metastatic prostate cancer. It can be used as part of a “doublet” approach (combined with standard hormone therapy) or a “triplet” approach (combined with both hormone therapy and chemotherapy), depending on how aggressive the cancer is.
Survival Benefits
In patients with high-volume metastatic hormone-sensitive prostate cancer, abiraterone combined with standard hormone therapy produced a median overall survival of about 50 months, compared to 34 months with hormone therapy alone. That’s roughly 16 additional months. It also outperformed chemotherapy with docetaxel in this population by about 4 months.
For patients with the most aggressive disease, the triplet combination of abiraterone, chemotherapy, and hormone therapy ranked as the most effective option, cutting the risk of death by nearly half compared to hormone therapy alone.
How It’s Taken
The standard dose is 1,000 mg taken by mouth once daily, alongside a corticosteroid taken twice daily. One important detail: abiraterone must be taken on an empty stomach. You should avoid eating for at least two hours before your dose and at least one hour afterward. Food significantly increases how much of the drug your body absorbs, which can amplify side effects unpredictably.
Common Side Effects
The most frequent side effects stem from that mineralocorticoid imbalance described earlier, even with the corticosteroid on board. About 22% of patients develop high blood pressure, 25% experience fluid retention or swelling, and 17% develop low potassium levels. These are manageable in most cases but require regular monitoring. Your medical team will check blood pressure frequently and order blood tests to track potassium and other electrolytes.
Liver function is another concern. The prescribing guidelines recommend liver blood tests every two weeks for the first three months of treatment, then monthly after that. Most liver enzyme elevations are mild and reversible, but catching them early is important because significant liver damage, though uncommon, can occur.
Drug Interactions to Know About
Abiraterone interferes with certain liver enzymes responsible for breaking down roughly one quarter of all medications. This means it can raise blood levels of drugs processed through the same pathways, potentially increasing their effects or side effects. Common examples include some antidepressants, certain pain medications like oxycodone, the heart medication amiodarone, and the seizure medication carbamazepine.
If you’re taking other medications, your oncologist will review potential interactions before starting treatment. This applies to over-the-counter drugs and supplements as well, since some are processed by the same enzymes abiraterone blocks.