Abiraterone

Key facts

• Abiraterone (sold as Zytiga and generics) blocks androgen production throughout the body. It is used together with a corticosteroid, usually prednisone, to treat prostate cancer that has spread and stopped responding to standard hormone therapy.
• You take it on an empty stomach: no food for at least two hours before the dose and one hour after, since food greatly increases how much of the drug you absorb.
• Abiraterone must always be combined with a low-dose corticosteroid. Without it, blocking hormone production lets a different hormone pathway run unchecked, causing high blood pressure, low potassium, and fluid retention.
• Regular blood tests for liver function, blood pressure, and potassium are required throughout treatment; report yellowing skin or eyes, severe weakness, or a pounding headache urgently.

What abiraterone treats

Abiraterone treats metastatic castration-resistant prostate cancer, prostate cancer that has spread beyond the prostate and keeps growing despite surgical or medical castration. It is given together with ongoing androgen deprivation therapy and a corticosteroid. It does not cure the disease and is not used for early or localized prostate cancer.

How abiraterone works

Prostate cancer cells depend on androgens to grow, even after the testicles' hormone production has been blocked. Abiraterone inhibits an enzyme called CYP17, which the adrenal glands, testes, and the tumor itself need to make androgens from cholesterol. Cutting off this remaining hormone supply slows tumor growth. Blocking the same enzyme also lowers cortisol, which is why a replacement corticosteroid is required alongside treatment.

Before you take it

• Do not take abiraterone during pregnancy; women who are or may become pregnant should not handle the tablets, and men should use a condom during sex with a pregnant partner, since the drug can pass into semen.
• Tell your doctor about liver disease; abiraterone is not recommended in moderate liver impairment and is avoided in severe impairment.
• Tell your prescriber about heart disease, arrhythmia, or heart failure, since the fluid retention and high blood pressure abiraterone can cause may worsen these conditions.
• Report any new symptoms of liver trouble right away: fatigue, nausea, abdominal pain, or yellowing skin or eyes.

Side effects

Common effects include fatigue, joint swelling or pain, high blood pressure, mild ankle swelling, low potassium, and stomach upset.

Stop and seek urgent medical care for any of these:

• Yellowing of the skin or eyes, dark urine, or severe abdominal pain, which can signal liver injury.
• Sudden weakness, dizziness, or fainting, which can signal adrenal insufficiency, especially during illness, injury, or a missed corticosteroid dose.
• A severe headache, chest pain, or an irregular heartbeat.

Safety essentials

• Never stop or skip the corticosteroid dose without medical advice; doing so removes your protection against dangerously high blood pressure, low potassium, and adrenal insufficiency.
• Liver function tests are required before starting and regularly during treatment; abiraterone is paused or the dose reduced if results worsen.
• Blood pressure and potassium are checked regularly, since abiraterone can push both to unsafe levels even when you feel well.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.