Zytiga

Zytiga comes as a tablet to take by mouth once a day.

The starting dose is typically 1,000 milligrams (mg), taken twice daily. It's usually taken along with 5 mg of prednisone.

Take this medicine on an empty stomach at least one hour before, or two hours after, eating any food.

Try to use Zytiga around the same time each day.

Follow the instructions on your prescription label carefully. Don't take more or less Zytiga than is recommended.

Swallow the tablet whole. Don't crush, chew, split, or break it.

Zytiga Overdose

If you suspect an overdose of Zytiga, contact a poison control center or emergency room immediately.

You can get in touch with a poison control center at 800-222-1222.

Missed Dose of Zytiga

If you miss a dose of Zytiga, skip it and continue with your regular medication schedule the next day.

Call your doctor for instructions if you miss more than one dose.

Abiraterone comes as a tablet to take by mouth on an empty stomach, 1 hour before or 2 hours after eating any food. It is usually taken once a day. Take abiraterone at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take abiraterone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the tablets whole with water; do not split, chew, or crush them.

Continue to take abiraterone even if you feel well. Do not stop taking abiraterone or prednisone without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• antifungal medicines such as itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend)
• clarithromycin (Biaxin, in Prevpac)
• HIV protease inhibitors including atazanavir (Reyataz), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), and saquinavir (Fortovase, Invirase)
• carbamazepine (Carbatrol, Epitol, Tegretol)
• phenobarbital (Luminal)
• phenytoin (Dilantin, Phenytek)
• nefazodone (Serzone)
• rifabutin (Mycobutin)
• rifampin (Rifadin, in Rifamate, in Rifater, Rimactane)
• rifapentine (Priftin)
• telithromycin (Ketek)
• thioridazine (Mellaril)
• nimodipine (Nimotop)
• St. John's wort

This is not a complete list of Zytiga drug interactions. Ask your doctor or pharmacist for more information.

If you take too much Zytiga, call your local Poison Control Center or seek emergency medical attention right away.

If Zytiga is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

• Store Zytiga at 59°F to 86°F (15°C to 30°C).
• Keep Zytiga and all medicines out of the reach of children.

Skip the missed dose and take the medicine the following day on an empty stomach (no food for at least 2 hours before or 1 hour after you take abiraterone). Do not take extra medicine to make up the missed dose.

Call your doctor for instructions if you miss more than one dose of abiraterone.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using abiraterone and call your doctor at once if you have:

• swelling in your ankles or feet, pain in your legs;

• pain or burning when you urinate;

• dangerously high blood pressure--severe headache, blurred vision, pounding in your neck or ears, nosebleed, anxiety, severe chest pain, shortness of breath;

• high blood sugar--increased thirst, increased urination, hunger, dry mouth, fruity breath odor, drowsiness, dry skin, blurred vision, weight loss;

• liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• low potassium--confusion, uneven heart rate, extreme thirst, increased urination, leg discomfort, muscle weakness or limp feeling; or

• signs of low adrenal gland hormones--worsening tiredness or muscle weakness, feeling light-headed, nausea, vomiting, loss of appetite, diarrhea, and weight loss.

Common side effects may include:

• vomiting, diarrhea, painful or difficult urination;

• swelling;

• feeling weak, feeling very hot;

• joint pain or swelling;

• bruising; or

• cough, feeling short of breath.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Absorption

Bioavailability

Abiraterone acetate is a prodrug that is converted in vivo to abiraterone; peak plasma abiraterone concentrations are attained about 2 hours after abiraterone acetate dose.1 5 13

Food

Food increases systemic exposure.1 8 13 Oral administration of a single 1-g dose of abiraterone acetate with a low-fat or high-fat meal increases abiraterone AUC by approximately fivefold or tenfold, respectively, and increases peak plasma concentrations by approximately sevenfold or 17-fold, respectively.1

Special Populations

In patients with mild (Child-Pugh class A) or moderate (Child-Pugh class B) hepatic impairment, AUC is increased 1.1- or 3.6-fold, respectively, compared with individuals with normal hepatic function.1

Distribution

Plasma Protein Binding

>99% (mainly albumin and α1-acid glycoprotein).1

Elimination

Metabolism

Abiraterone acetate is hydrolyzed to abiraterone (active metabolite), most likely by esterases in non-CYP-dependent pathways.1 Further metabolized to 2 inactive sulfate conjugates, abiraterone sulfate (formed by SULT2A1, a sulfotransferase that catalyzes sulfate conjugation of dehydroepiandrosterone [DHEA] and other steroids) and N-oxide abiraterone sulfate (formed by CYP3A4 and SULT2A1).1 19

Elimination Route

Excreted in feces (88%), mainly as abiraterone acetate (55%) and abiraterone (22%), and in urine (5%).1

Half-life

Approximately 12 hours.1

Special Populations

Mean half-life in patients with mild or moderate hepatic impairment is approximately 18 hours or 19 hours, respectively.1

In patients with end-stage renal disease requiring hemodialysis, pharmacokinetic parameters were similar to those in individuals with normal renal function.1

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• Bladder pain
• bloating or swelling of the face, arms, hands, lower legs, or feet
• bloody or cloudy urine
• blurred vision
• bone fracture
• chest pain or discomfort
• convulsions
• decreased urine
• difficult, burning, or painful urination
• dizziness
• dry mouth
• fainting
• fast, pounding, or irregular heartbeat or pulse
• feeling of warmth
• frequent urge to urinate
• headache
• increased need to urinate
• increased thirst
• increased urge to urinate during the night
• lightheadedness, dizziness, or fainting
• loss of appetite
• lower back or side pain
• mood changes
• muscle pain or cramps
• nausea or vomiting
• nervousness
• numbness or tingling in the hands, feet, or lips
• pain or swelling in the arms or legs without any injury
• passing urine more often
• pounding in the ears
• rapid weight gain
• redness of the face, neck, arms, and occasionally, upper chest
• slow heartbeat
• sudden sweating
• swelling
• swelling with pits or depressions on the skin
• unusual tiredness or weakness
• unusual weight gain or loss
• waking to urinate at night

• Abdominal or stomach pain or tenderness
• arm, back, or jaw pain
• chest tightness or heaviness
• clay colored stools
• cool, sweaty skin
• dark urine
• decreased appetite
• decreased urine output
• difficulty with breathing
• dilated neck veins
• extreme fatigue
• fever
• headache
• irregular breathing
• itching skin or rash
• sweating
• swelling of the face, fingers, feet, or lower legs
• weakness
• weight gain
• yellow eyes or skin

• Darkening of the skin
• diarrhea
• mental depression

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Acid or sour stomach
• belching
• body aches or pain
• chills
• cough
• difficulty with moving
• ear congestion
• heartburn
• indigestion
• joint pain
• loss of voice
• muscle cramps or spasms
• muscle or bone pain
• muscle stiffness
• nasal congestion
• runny nose
• sneezing
• sore throat
• stomach discomfort or upset
• swelling or stiffness of the joints

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Zytiga is a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer.

Zytiga (abiraterone) works by reducing androgen production in the body. Androgens are male hormones that can promote tumor growth in the prostate gland.

Zytiga is used together with prednisone to treat prostate cancer that has spread to other parts of the body.

Zytiga is used in men whose prostate cancer cannot be treated with surgery or other medicines.

Usual Adult Dose for Prostate Cancer:

Initial dose: 1000 mg orally once daily.

Zytiga should be administered in combination with prednisone 5 mg orally twice daily.

Zytiga is used to treat castration-resistant prostate cancer in men. It’s given when the cancer has spread to other parts of your body.

Zytiga is available as a tablet you take by mouth.

Zytiga is a brand name for the drug abiraterone. It isn’t available as a generic drug.

The more common side effects of Zytiga can include muscle pain, joint pain or swelling, heartburn, and flushing (reddening and warming of your skin). They can also include cough, weakness, diarrhea, and vomiting.

In some cases, Zytiga can cause serious side effects. These can include high blood pressure, low potassium levels, fluid retention, and liver problems.

• Pregnancy See Details

What is Zytiga?

This drug is a prescription drug. It’s available as a tablet you take by mouth.

This drug is only available as the brand-name drug Zytiga. It isn’t available as a generic drug.

This drug is used as part of a combination therapy. You have to take it with a drug called prednisone. Do not stop taking either drug without speaking to your doctor.

Why it's used

This drug is used to treat castration-resistant prostate cancer in men. This is a type of prostate cancer that doesn’t respond to medical or surgical treatments that lower testosterone. This drug is used when the cancer has spread to other parts of your body. This drug is given with prednisone.

How it works

This drug belongs to a class of drugs called androgen biosynthesis inhibitors. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

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