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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Zytiga
Generic Name
Abiraterone Acetate
Active Ingredient
AbirateroneCategory
Other
Salt Form
Acetate
Variants
2
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Zytiga, you must consult a qualified healthcare professional.
Detailed information about Zytiga
Abiraterone acetate is a potent CYP17 inhibitor used primarily to treat metastatic castration-resistant and high-risk castration-sensitive prostate cancer, typically administered alongside a corticosteroid.
The standard adult dosage for Abiraterone acetate depends on the specific formulation being used and the condition being treated.
Some newer formulations of abiraterone (such as Yonsa) use a micronized technology that allows for a lower dose (e.g., 500 mg daily) because the drug is absorbed more efficiently. It is critical to confirm which formulation you have been prescribed, as they are not interchangeable on a milligram-for-milligram basis.
Abiraterone is not indicated for use in the pediatric population. Prostate cancer is a disease of adult males, and the safety and efficacy of this medication in children or adolescents have not been established. It should not be administered to individuals under the age of 18.
For patients with pre-existing kidney disease (renal impairment), no initial dosage adjustment is typically necessary. The drug is not significantly cleared by the kidneys.
Because Abiraterone is metabolized by the liver, patients with liver issues require careful monitoring:
No specific dosage adjustments are required based solely on age; however, elderly patients may be more susceptible to cardiac side effects or complications from fluid retention and should be monitored closely.
If you miss a dose of Abiraterone, skip the missed dose and take your usual dose the following day. Do not take two doses at once to make up for a missed one. If you miss more than one dose, contact your healthcare provider immediately for instructions.
There is no specific antidote for an Abiraterone overdose. If an overdose occurs, stop taking the medication and seek emergency medical attention or contact a poison control center. Treatment will focus on supportive care, including monitoring liver function and heart rhythm.
> Important: Follow your healthcare provider's dosing instructions precisely. Do not adjust your dose or stop the medication without medical guidance, as this could cause your cancer to progress or lead to adrenal complications.
Most patients taking Abiraterone will experience some level of side effects, many of which are related to the hormonal changes the drug induces. Common effects include:
Abiraterone is a potent medication that requires careful medical supervision. The most critical safety concern is the risk of liver damage and the potential for severe cardiovascular strain due to hormonal shifts. Patients must adhere to all scheduled blood tests and blood pressure checks to ensure the drug is being processed safely by the body.
No FDA black box warnings for Abiraterone. However, the FDA-approved labeling includes strong warnings regarding Hepatotoxicity and Adrenocortical Insufficiency.
While there are few absolute contraindications, Abiraterone should not be used with certain drugs that drastically alter its concentration or where the combined toxicity is too high:
Conditions where Abiraterone must NEVER be used include:
Abiraterone is not for use in women. It is highly teratogenic (causes birth defects). According to FDA labeling, Abiraterone is contraindicated in pregnancy. There are no human data on the use of Abiraterone in pregnant women, but its mechanism of action—blocking androgen synthesis—is essential for normal fetal development. Male patients with female partners of reproductive potential must use effective contraception (such as condoms) during treatment and for three weeks after the final dose, as the drug may be present in semen.
Abiraterone is not indicated for use in women. It is unknown if the drug or its metabolites are excreted in human milk. Because of the potential for serious adverse reactions in a nursing infant, the drug is not to be used by breastfeeding mothers.
The safety and effectiveness of Abiraterone in pediatric patients have not been established. It is not used in children. There is a theoretical risk that the drug could interfere with normal puberty and growth due to its profound effect on sex hormones.
Abiraterone acetate is an orally active inhibitor of the enzyme CYP17 (17α-hydroxylase/C17,20-lyase). This enzyme is expressed in testicular, adrenal, and prostatic tumor tissues. It is required for the biosynthesis of androgens. Specifically, CYP17 catalyzes two sequential reactions: the conversion of pregnenolone and progesterone into their 17α-hydroxy derivatives, and the subsequent formation of the androgen precursors dehydroepiandrosterone (DHEA) and androstenedione. By inhibiting these steps, Abiraterone reduces the levels of circulating testosterone and other androgens to near-zero levels.
The primary pharmacodynamic effect of Abiraterone is the reduction of serum testosterone. In clinical trials, the administration of 1,000 mg daily resulted in a decrease of serum testosterone to below the limit of detection (typically <1 ng/dL) within days. Because it also blocks cortisol synthesis, there is a compensatory rise in Adrenocorticotropic Hormone (ACTH), which can drive mineralocorticoid excess. This is why co-administration of prednisone is pharmacodynamically necessary to suppress ACTH and maintain cortisol-like activity.
| Parameter | Value |
Common questions about Zytiga
Abiraterone is primarily used to treat two forms of advanced prostate cancer: metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC). It is designed for patients whose cancer has spread beyond the prostate to other parts of the body, such as the bones or lymph nodes. The drug works by blocking the production of testosterone from all sources in the body, which effectively starves the cancer cells of the hormones they need to grow. Because it is a potent hormone therapy, it is almost always used in combination with a corticosteroid like prednisone to prevent specific hormonal side effects. It is considered a standard-of-care treatment that has been shown to improve survival rates in men with advanced disease.
The most common side effects associated with Abiraterone include fatigue, joint pain, swelling in the legs or feet (edema), and hot flashes. Many patients also experience 'mineralocorticoid excess' symptoms, such as high blood pressure and low potassium levels in the blood, which can cause muscle weakness or heart palpitations. Digestive issues like diarrhea and nausea are also frequently reported, though these are often mild. Because the drug affects the liver, elevations in liver enzymes are common and require regular blood test monitoring. While many side effects are manageable, it is crucial to report any significant changes in how you feel to your oncology team immediately.
There is no known direct chemical interaction between Abiraterone and alcohol that would make moderate drinking strictly forbidden. However, both Abiraterone and alcohol are processed by the liver, and Abiraterone carries a known risk of causing liver toxicity or inflammation. Consuming significant amounts of alcohol could theoretically increase the strain on your liver and make it harder for your doctor to determine if the drug is causing liver damage. Furthermore, alcohol can worsen side effects like fatigue and dehydration, which are already common with this treatment. It is generally recommended to limit alcohol intake and consult with your healthcare provider regarding what is safe for your specific liver health.
Abiraterone is absolutely not safe for use during pregnancy and is strictly contraindicated for women. The drug works by blocking the synthesis of androgens, which are vital for the normal development of a fetus, particularly a male fetus. Exposure to Abiraterone during pregnancy can cause severe birth defects or fetal death. Interestingly, the drug can be absorbed through the skin, so women who are pregnant or may become pregnant should not even handle the tablets without protective gloves. For male patients, it is essential to use highly effective contraception, such as condoms, during sexual activity with a female partner of childbearing age to prevent any potential exposure through semen.
Abiraterone begins working at the molecular level almost immediately after the first few doses, with testosterone levels typically dropping to near-zero within the first week of treatment. However, the clinical effects—such as a decrease in PSA (Prostate-Specific Antigen) levels or a reduction in bone pain—may take several weeks or even a few months to become fully apparent. Doctors usually monitor PSA levels every month to gauge how well the medication is working. It is important to remember that Abiraterone is a long-term treatment intended to control the cancer rather than provide an immediate 'cure.' Your oncology team will use regular imaging scans and blood tests to determine the drug's ongoing effectiveness over time.
You should never stop taking Abiraterone or the accompanying prednisone suddenly without consulting your doctor. Stopping Abiraterone can allow your prostate cancer to begin growing and spreading again rapidly. More dangerously, stopping the prednisone that is taken with Abiraterone can lead to an 'adrenal crisis,' a life-threatening condition where your body does not have enough cortisol to function. Symptoms of an adrenal crisis include severe weakness, confusion, very low blood pressure, and fainting. If the medication needs to be discontinued due to side effects or treatment failure, your doctor will provide a safe plan to transition you off the drugs or onto a different therapy.
If you miss a dose of Abiraterone, you should skip that dose entirely and take your next regularly scheduled dose the following day. It is important not to 'double up' or take two doses at the same time to make up for the missed one, as this could significantly increase the risk of toxicity. If you miss more than one dose in a row, you should contact your healthcare provider's office for guidance. Consistency is key with this medication, so try to take it at the same time every day, ensuring you follow the 'empty stomach' rule (no food 2 hours before or 1 hour after the dose).
Weight gain is a possible side effect of Abiraterone, though it is often more related to the overall hormone therapy process and the use of prednisone. Androgen deprivation therapy (ADT) naturally leads to a decrease in muscle mass and an increase in body fat because testosterone plays a major role in metabolism and muscle maintenance. Additionally, the prednisone taken alongside Abiraterone can cause fluid retention and increased appetite, both of which contribute to weight changes. Many patients find that maintaining a healthy diet and engaging in regular resistance exercise can help mitigate these metabolic changes. If you notice rapid or excessive weight gain, especially if accompanied by swelling, notify your doctor.
Abiraterone can be taken with many other medications, but it has several significant drug interactions that require careful management. It is a known inhibitor of the CYP2D6 enzyme, meaning it can increase the levels of drugs like certain antidepressants, antipsychotics, and heart medications in your blood. It also interacts with 'strong inducers' of the CYP3A4 enzyme, such as rifampin or certain seizure medications, which can make Abiraterone less effective. Because of these complexities, you must provide your doctor with a complete list of all prescription drugs, over-the-counter medicines, and herbal supplements (like St. John's Wort) you are taking. Your pharmacist can also perform a comprehensive interaction check.
Yes, Abiraterone acetate is available as a generic medication. The original brand-name version, Zytiga, lost its patent exclusivity several years ago, allowing multiple manufacturers to produce generic versions. Generic Abiraterone is required by the FDA to have the same active ingredient, strength, dosage form, and route of administration as the brand-name drug. It must also be 'bioequivalent,' meaning it works in the body in the same way. The availability of generic Abiraterone has significantly reduced the cost of treatment for many patients. However, some newer formulations (like micronized versions) may still be under brand-name protection and are not interchangeable with standard generic Abiraterone.
Other drugs with the same active ingredient (Abiraterone)
> Warning: Stop taking Abiraterone and call your doctor immediately if you experience any of the following serious symptoms:
Prolonged use of Abiraterone can lead to cumulative effects on the body:
Currently, Abiraterone does not carry an FDA Black Box Warning. However, it does carry significant 'Warnings and Precautions' regarding hepatotoxicity (liver toxicity) and mineralocorticoid excess. The FDA requires regular monitoring of liver function tests (ALT, AST, and bilirubin) before starting treatment and every two weeks for the first three months of therapy.
Report any unusual symptoms to your healthcare provider immediately. Early detection of side effects often allows for dose adjustments that can keep you on the medication safely.
Patients on Abiraterone require a rigorous monitoring schedule:
Abiraterone is not known to cause significant impairment of the central nervous system. However, because fatigue is a very common side effect, patients should assess their level of alertness before driving or operating heavy machinery.
There is no direct contraindication between alcohol and Abiraterone; however, alcohol can strain the liver. Given that Abiraterone has a risk of hepatotoxicity, it is generally advised to limit alcohol consumption while on this medication. Discuss your alcohol intake with your oncologist.
Do not stop taking Abiraterone or Prednisone abruptly. If Abiraterone is stopped, the cancer may begin to grow more rapidly. If Prednisone is stopped suddenly, you may experience a life-threatening adrenal crisis. If the medication must be stopped, your doctor will provide a specific tapering schedule.
> Important: Discuss all your medical conditions, especially liver disease, heart problems, or a history of diabetes, with your healthcare provider before starting Abiraterone.
For each major interaction, the mechanism usually involves the Cytochrome P450 enzyme system. When Abiraterone inhibits an enzyme (like CYP2D6), other drugs that need that enzyme to be cleared stay in the body longer, leading to toxicity. Conversely, when another drug induces an enzyme (like CYP3A4), Abiraterone is cleared too quickly, leading to treatment failure.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, including over-the-counter pain relievers and vitamins.
Conditions requiring careful risk-benefit analysis by a specialist:
There is no established cross-sensitivity with other common drugs, though patients who have had severe reactions to other steroid-synthesis inhibitors should be monitored closely for similar hypersensitivity reactions.
> Important: Your healthcare provider will evaluate your complete medical history, including liver health and cardiac status, before prescribing Abiraterone.
The majority of patients in clinical trials for Abiraterone were 65 years of age and older (over 70% in some studies). No overall differences in safety or effectiveness were observed between these elderly patients and younger adult patients. However, older patients are more likely to have pre-existing heart conditions or be taking multiple other medications (polypharmacy), which increases the risk of drug interactions and fluid-retention-related complications like congestive heart failure.
In clinical studies, no significant difference in the pharmacokinetics of abiraterone was observed between subjects with normal kidney function and those with end-stage renal disease on dialysis. Therefore, no dose adjustment is necessary for patients with renal impairment. It is not removed by hemodialysis.
The liver is the primary site of metabolism for Abiraterone. In patients with moderate hepatic impairment (Child-Pugh Class B), the systemic exposure (AUC) of the drug increases by nearly four-fold. Consequently, the dose is reduced to 250 mg once daily. For those with severe impairment (Class C), the exposure increases even more, making the drug unsafe for use.
> Important: Special populations, particularly those with liver or heart disease, require individualized medical assessment and more frequent laboratory monitoring.
|---|---|
| Bioavailability | <10% (Fasted); Increases up to 10x with food |
| Protein Binding | >99% (Albumin and Alpha-1 acid glycoprotein) |
| Half-life | 12 - 15 hours |
| Tmax | 2 hours |
| Metabolism | Hepatic (CYP3A4 and SULT2A1) |
| Excretion | Fecal ~88%, Renal ~5% |
Abiraterone is classified as a CYP17 enzyme inhibitor. It is part of the broader category of 'Next-Generation Anti-Androgens' or 'Androgen Synthesis Inhibitors.' It is distinct from 'Androgen Receptor Antagonists' like Enzalutamide, which block the receptor rather than the production of the hormone itself.