Abiraterone belongs to the class of medications called androgen biosynthesis inhibitors. It is taken along with the medication prednisone to treat metastatic prostate cancer (cancer that has spread to other parts of the body) when other treatments have failed. It stops your body from making testosterone, a male hormone that is involved in the growth of prostate cancer.

If you are taking another medication, such as a GnRH agonist, continue to take this medication until your doctor tells you otherwise.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual recommended adult dose of abiraterone is 1,000 mg taken by mouth once daily. Abiraterone is usually taken along with another medication called prednisone.

Abiraterone must be taken on an empty stomach. Do not eat any solid food or drink any liquids for 2 hours before taking abiraterone or for at least 1 hour after taking abiraterone. Taking this medication with food causes the medication to be absorbed into the body quickly and may cause increased side effects. Swallow the medication whole with water. Do not break or crush the tablets.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

250 mg
Each uncoated, white-to-off-white oval tablet, debossed with "AA250" on one side, contains 250 mg of abiraterone. Nonmedicinal ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, povidone, sodium lauryl sulfate, magnesium stearate, and colloidal silicon dioxide.

500 mg
Each film-coated, purple, oval tablet debossed with "AA" on one side and "500" on the other contains 500 mg of abiraterone. Nonmedicinal ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, silicified microcrystalline cellulose, and sodium lauryl sulfate. Film coating: iron oxide black, iron oxide red, macrogol 3350, polyvinyl alcohol, talc, and titanium dioxide.

Who should not take this medication?

Do not take abiraterone if you:

• are allergic to abiraterone or any ingredients of the medication
• are or may be pregnant

Do not take abiraterone if you:

• are allergic to abiraterone or any ingredients of the medication
• are or may be pregnant

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• constipation
• cough
• diarrhea
• difficulty sleeping
• falls
• fatigue
• headache
• heartburn
• hot flushes
• joint pain or swelling
• muscle pain
• nausea
• skin rash
• vomiting
• weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abnormal heart rhythms (such as fast or slow heart rate, palpitations)
• blood in urine
• bruising
• chest pain
• cold-like symptoms (e.g., runny nose, nasal congestion, sore throat)
• fainting
• fluid build-up (e.g., swollen or puffy ankles, feet, or legs)
• fractures
• increased cholesterol levels
• increased blood pressure (e.g., shortness of breath, dizziness, fainting, chest pain or pressure, ankle or leg swelling, bluish colour to lips and skin, racing or pounding heartbeat)
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of heart problems (e.g., fast, irregular heartbeat or pulse, chest pain, difficulty breathing)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of low potassium levels (e.g., muscle twitches, weakness, or a pounding heartbeat)
• signs of muscle damage (e.g., muscle pain, tenderness or weakness, or brown or discoloured urine)
• signs of pneumonia (e.g., fever, chills, shortness of breath, cough)
• symptoms of decreased adrenal gland function (e.g., body aches, fatigue, low blood pressure, light-headedness, loss of body hair, skin discolouration, unexplained weight loss)
• symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Diabetes: People with diabetes who are taking medications such as repaglinide or pioglitazone, may experience increase levels of blood glucose as a result of adding abiraterone. If you have diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Fluid and electrolyte balance: Abiraterone may cause your body to retain fluid and the level of potassium in your blood to change while taking this medication. If you experience symptoms of fluid and low potassium levels such as muscle weakness, muscle twitches, or a pounding, racing heartbeat, contact your doctor as soon as possible. Your doctor will do blood tests regularly to monitor the levels of the electrolytes in your blood while you are taking this medication.

Heart disease: The effects of abiraterone on people with heart disease have not been studied. Abiraterone can cause increased blood pressure and fluid retention, which may affect how well your heart works. If you have a history of heart disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

Abiraterone may reduce liver function and can cause liver failure. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Muscle effects: In rare cases, serious muscle damage has been associated with the use of abiraterone. Your risk may be increased if you are taking other medications which can cause this effect (i.e., "statin" cholesterol-lowering medications). Report any unexplained muscle pain, tenderness, weakness or cramps, or any brown or discoloured urine to your doctor immediately, particularly if you are also experiencing malaise (a general feeling of being unwell) or fever.

Pregnancy: It is not known if abiraterone is found in semen. If you are engaged in sexual activity with a pregnant person, a condom should be used. If you are engaged in sexual activity with a person who may become pregnant, a condom and a second effective method of birth control should be used. Condoms must be used during treatment with abiraterone and for one week after treatment has ended.

Due to the way that abiraterone works, it is possible that exposure to this medication during pregnancy may harm the developing baby. To prevent accidental exposure to abiraterone, women who handle these tablets should wear gloves.

Breast-feeding: It is not known if abiraterone passes into breast milk. To prevent accidental exposure to abiraterone, those who could become pregnant should wear gloves when handling these tablets.

Children: The safety and effectiveness of using this medication have not been established for children.

There may be an interaction between abiraterone and any of the following:

• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• anticancer medications (e.g., dacarbazine, docetaxel, doxorubicin, etoposide, ifosfamide, irinotecan, mitotane, paclitaxel, vincristine)
• antipsychotics (e.g., aripiprazole, clozapine, haloperidol, risperidone)
• apalutamide
• atomoxetine
• beta-adrenergic blockers (e.g., carvedilol, metoprolol, propranolol)
• bosentan
• carbamazepine
• codeine
• dabrafenib
• dextromethorphan
• doxepin
• efavirenz
• eliglustat
• enzalutamide
• eslicarbazepine
• flecainide
• lumacaftor and ivacaftor
• lorlatinib
• metoclopramide
• modafinil
• paroxetine
• phenobarbital
• phenytoin
• pioglitazone
• pitolisant
• primidone
• propafenone
• repaglinide
• rifabutin
• rifampin
• ropinirole
• St. John's wort
• spironolactone
• “statins” (e.g., atorvastatin, rosuvastatin, simvastatin)
• tamoxifen
• tamsulosin
• testosterone
• tetrabenazine
• tramadol
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• vortioxetine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication.Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.