Zytiga is in the class of medications called cytochrome P450 (CYP) 17 inhibitors. Testosterone is used by prostate cancer cells as fuel for growth. This medication works by decreasing testosterone production in the testes, adrenal glands, and prostate cancer cells.
Zytiga is available as a tablet to be taken by mouth.
What Is Zytiga Used For?
Zytiga is used to treat metastatic castration-resistant prostate cancer (CRPC) and metastatic high-risk castration-sensitive prostate cancer (CSPC) as part of a regimen to help reduce testosterone in the body. When prostate cancer grows, it uses testosterone as fuel to keep growing. Decreasing testosterone production can help slow prostate cancer growth.
Brand Name(s): Zytiga
Drug Availability: Prescription
Administration Route: Oral
Therapeutic Classification: CYP17 inhibitor
Available Generically: Yes
Controlled Substance: N/A
Active Ingredient: Abiraterone acetate
Dosage Form(s): Tablet
Zytiga is given along with another testosterone-lowering medication called a gonadotropin-releasing hormone. It is also used in combination with prednisone, a steroid, daily.
How to Take Zytiga
Take Zytiga as prescribed, usually once a day and on an empty stomach (at least one hour before or two hours after eating). Taking this medication with food may affect its absorption in the body, potentially leading to side effects.
The tablets must be swallowed whole and not broken or crushed. You can take the tablets with water.
Storage
Keep the tablets at room temperature and in the original packaging. It is important that the tablets are kept away from children and that pregnant people do not handle the medication.
What Are the Side Effects of Zytiga?
This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 800-FDA-1088.
Common Side Effects
There may be side effects when taking Zytiga. The most common side effects include:
Feeling tiredHot flashesHigh blood pressureJoint painFluid retentionDiarrheaNauseaHeadacheRespiratory infectionCough
The most common laboratory abnormalities include:
Low red blood cells (anemia) High cholesterol Elevated blood sugar Low white blood cells (neutropenia) Elevated liver enzymes
Severe Side Effects
Call your healthcare provider immediately if you have serious side effects. Call 911 if you feel your symptoms are life-threatening. Serious side effects and their symptoms can include the following:
Severely elevated blood pressure Low potassium levels. Symptoms can include muscle spasms, fatigue, abnormal heart rhythm, and weakness. Adrenal insufficiency: Symptoms can include fatigue, weakness, joint pain, and weight loss. Liver toxicity: Signs or symptoms can include elevated liver tests, abdominal pain, and yellowing of the skin or eyes (jaundice).
Dosage: How Much Zytiga Should I Take?
Modifications
For people with pre-existing liver disease, the starting dose of Zytiga will be decreased. A lower dose may also be needed if liver dysfunction develops while taking the medication.
If you experience a serious side effect, you or your healthcare provider may send a report to the FDA’s MedWatch Adverse Event Reporting Program or by phone (800-332-1088).
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
For oral dosage form (tablets): For castration-resistant prostate cancer: Adults—1000 milligrams (mg) (two 500 mg tablets or four 250 mg tablets) once a day, taken together with 5 mg oral prednisone 2 times a day. Children—Use is not recommended. For high-risk castration-sensitive prostate cancer: Adults—1000 milligrams (mg) (two 500 mg tablets or four 250 mg tablets) once a day, taken together with 5 mg oral prednisone once a day. Children—Use is not recommended.
Missed Dose
If you miss a dose of Zytiga, take it as scheduled the next day. Missed doses should not be doubled.
Overdose: What Happens If I Take Too Much Zytiga?
Notify a healthcare provider immediately if you take more Zytiga than prescribed. Your healthcare provider may decide to monitor your reaction with lab values, such as liver tests, and by measuring your blood pressure and heart rhythm.
Precautions
What Are Reasons I Shouldn’t Take Zytiga?
Pregnant people should not take or handle Zytiga, as it can cause significant fetal harm.
If someone collapses or isn’t breathing after taking Zytiga, call 911 immediately.
Women and children should not use this medicine. Pregnant women or women who may become pregnant should not handle or touch the tablets without protection (eg, gloves). This medicine may also cause birth defects if the father is using it when his sexual partner becomes pregnant. You must use a condom and another effective method of birth control during treatment with this medicine and for 3 weeks after the last dose. If a pregnancy occurs while you are using this medicine, tell your doctor right away.
You will also need to have your blood pressure measured before starting this medicine and while you are using it. If you notice any changes to your recommended blood pressure, call your doctor right away. If you have questions about this, talk to your doctor.
Do not interrupt or stop using this medicine together with prednisone without first asking your doctor. This may increase your risk of having adrenal gland problems. Talk to your doctor if you have darkening of the skin, diarrhea, dizziness, fainting, loss of appetite, mental depression, nausea, skin rash, unusual tiredness or weakness, or vomiting.
Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.
Abiraterone and prednisone/prednisolone may increase your risk for bone fractures and death when used together with radium 223 dichloride (radiation treatment). Tell your doctor if you are having any other treatment for your prostate cancer.
This medicine may cause hypoglycemia (low blood sugar), especially if you have diabetes and take certain medicines for diabetes. Check with your doctor right away if you have anxiety, blurred vision, chills, cold sweats, coma, confusion, cool, pale skin, depression, dizziness, fast heartbeat, headache, increased hunger, nausea, nervousness, nightmares, seizures, shakiness, slurred speech, or unusual tiredness or weakness.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Also, you should not take Zytiga if you have severe liver disease.
What Other Medications Interact With Zytiga?
Some medications should be avoided if possible while taking Zytiga. Before using this medication, tell your healthcare provider all the medications, over-the-counter (OTC) products, and herbal supplements that you are taking. If any of these cannot be stopped, a dose reduction of Zytiga may be necessary.
These medications include, but may not be limited to:
Dilantin (phenytoin) Tegretol (carbamazepine) Rifampin, also known as rifampicin
Other drug interactions may occur with Zytiga. Tell your healthcare provider about all medications, vitamins, and herbal supplements you take.
What Medications Are Similar?
Many medications are available to treat prostate cancer. However, not all of them work the same way as Zytiga. Unlike Zytiga, which suppresses testosterone, some instead block the ability of testosterone to attach to the cancer cell.
Ketoconazole is one medication that works similarly to Zytiga. It should not be used in combination with Zytiga.
Other medications used to treat prostate cancer include:
Casodex (bicalutamide) Lynparza (olaparib) Erleada (apalutamide)
How Can I Stay Healthy While Taking Zytiga?
Although being diagnosed with prostate cancer can be overwhelming, remember that many effective treatments are available. Prostate cancer generally comes with a good prognosis for the average person, especially compared with other cancers. Still, undergoing cancer treatment can be a physical and emotional adjustment for many people.
FatigueHot flashesJoint painHeadacheWeakness
Communicate with your oncologist and follow all instructions for taking your medication. Ask for a written-out treatment plan or other suggestions if you have trouble remembering what to do. It’s important to take your medication exactly as prescribed to get the best results.
If you’re worried about the financial toll of treatment, there are options for cost assistance for those with cancer. Your healthcare team may also be able to direct you to financial assistance programs.
Discuss any questions or concerns about side effects or how to take your medication with the oncology care team.
