Abiraxen 250 mg (Abiraterone Acetate): A Zytiga Alternative for Advanced Prostate Cancer

Abiraxen is a generic version of the prostate cancer medicine abiraterone acetate, made by Everest Pharmaceuticals in Bangladesh. It is taken as four tablets once a day, always alongside a steroid called prednisone, and always on an empty stomach. It works by shutting down the body’s production of testosterone, which most prostate cancers need in order to grow. As a Zytiga alternative supplied through the Named Patient Program, it is available to patients outside Bangladesh who already hold a valid prescription. This page explains what it treats, how it is taken, what to watch for, and how to access it.

What Is Abiraxen (Abiraterone Acetate)?

Abiraxen contains abiraterone acetate, the same active ingredient, at the same 250 mg strength, as the originator product Zytiga. It is manufactured by Everest Pharmaceuticals in Bangladesh under WHO-GMP quality standards and supplied internationally under Named Patient Program (NPP) frameworks.

Abiraterone acetate as a molecule was first approved by the U.S. FDA in 2011. That approval history belongs to the originator and to branded products such as Zytiga. Abiraxen itself is not an FDA-approved product. It is a generic manufactured to WHO-GMP standards, made available through the Named Patient route that governs access to medicines not registered in a patient’s own country.

Read This Before You Start: Not All Abiraterone Is Dosed the Same Way

There is more than one form of abiraterone on the world market, and they are not interchangeable. The FDA label itself carries a medication-error warning about this.

If you have been switched between brands or strengths, confirm the dose and the food instructions with your oncologist before taking the first tablet. Applying one product’s instructions to the other can result in a substantial overdose or underdose.

How Abiraterone and Prednisone Work Together

Most prostate cancer cells need androgens, chiefly testosterone, to grow. Standard hormone therapy (either injections that suppress the testicles, or their surgical removal) lowers testosterone produced by the testes. But the adrenal glands and the tumour itself can keep producing androgens independently, which is how cancer eventually starts growing again despite hormone therapy.

Abiraterone acetate converts in the body to abiraterone, which blocks an enzyme called CYP17. That enzyme is present in the testes, the adrenal glands, and in prostate tumour tissue, and it is required to make androgens in all three places. Blocking it cuts off androgen supply more completely than testicular suppression alone.

Blocking CYP17 has a side consequence: it disrupts the adrenal glands’ production of cortisol and increases production of hormones that raise blood pressure and lower potassium. This is why abiraterone is never taken alone. Prednisone replaces the missing cortisol and keeps that hormonal imbalance in check. Skipping prednisone is not a minor omission; it is what causes the dangerous blood pressure and potassium problems described further down this page.

Abiraterone also does not replace your existing hormone therapy. Patients continue their GnRH injections (or remain post-orchiectomy) throughout treatment.

Abiraterone Acetate Uses: What Abiraxen Treats

Abiraterone acetate with prednisone is indicated for two settings in prostate cancer. Both are full, traditional approvals, not accelerated approvals.

Metastatic castration-resistant prostate cancer (mCRPC) — cancer that has spread and is growing again despite hormone therapy. Approved in 2011 for patients who had already had chemotherapy, and extended in 2012 to those who had not.

Metastatic high-risk castration-sensitive prostate cancer (mCSPC) — cancer that has spread but still responds to hormone therapy, in patients with high-risk features. Approved February 2018. “High-risk” here means at least two of: a Gleason score of 8 or above (a measure of how aggressive the cancer looks under a microscope), three or more spots on a bone scan, or cancer measurably spread to an organ. <details> <summary><strong>Clinical trial data (for readers who want the numbers)</strong></summary>

Three randomised placebo-controlled trials established efficacy. Figures below are taken from the current FDA prescribing information and are dated to the follow-up period stated in each analysis.

In COU-AA-302, time to needing chemotherapy was also delayed, at a median of 25.2 months versus 16.8 months. In LATITUDE, median time to starting chemotherapy was not reached in the treatment arm versus 38.9 months on placebo.

These are originator-drug trials. Everest has not published independent bioequivalence data for Abiraxen that we have been able to verify. As a generic containing the same active ingredient at the same strength, manufactured to WHO-GMP standards, it is expected to perform comparably. We make no bioequivalence claim. </details>

Abiraterone Dosage and Administration

Standard dose: 1,000 mg once daily — four 250 mg tablets taken together, as a single dose.

The prednisone dose depends on the setting:

• mCRPC: prednisone 5 mg twice daily
• mCSPC: prednisone 5 mg once daily

⚠️ The empty-stomach rule

No food for 2 hours before your dose. No food for 1 hour after.

This is the single most important instruction on this page. Taking abiraterone with food dramatically increases how much drug enters your bloodstream:

• With a low-fat meal: peak drug level roughly 7 times higher, total exposure roughly 5 times higher
• With a high-fat meal: peak drug level roughly 17 times higher, total exposure roughly 10 times higher

Because the fat content of meals varies, taking it with food produces unpredictable exposure, which is why the rule is absolute rather than a suggestion. Many patients find bedtime or first thing in the morning easiest to manage.

Swallow the tablets whole with water. Do not crush, break, or chew them.

Do not stop or adjust the prednisone on your own, including during illness, infection, or before surgery. Steroid requirements change in those situations and stopping abruptly can trigger a serious drop in adrenal function.

If You Miss a Dose

Take your normal dose the following day. Do not take extra tablets to make up for a missed dose. If you miss more than one day, contact your oncologist before restarting.

Dose Adjustments

If Liver Enzymes Rise During Treatment

Liver injury is the most common reason abiraterone is interrupted. The prescribing information sets out a specific stepwise approach, which your oncologist will follow:

After restarting, liver tests are checked at least every two weeks for three months, then monthly.

Monitoring Schedule

Warnings and Precautions

Abiraterone acetate does not carry an FDA boxed warning. The label lists no contraindications. It does carry several warnings that require active monitoring rather than passive awareness.

Liver toxicity. Can be severe. Fulminant hepatitis, acute liver failure, and deaths have been reported after the drug reached market. In pooled trial data, significant liver enzyme rises occurred in about 6% of patients, typically within the first three months. Patients whose liver enzymes were already elevated before starting were more likely to have problems. Report yellowing of the skin or eyes, dark urine, or severe nausea or vomiting immediately.

High blood pressure, low potassium, and fluid retention. These stem directly from how the drug works. In the LATITUDE trial, severe (grade 3-4) high blood pressure occurred in 20% of patients on abiraterone versus 10% on placebo, and severe low potassium in 10% versus 1.3%. Blood pressure and potassium should be controlled before starting and monitored at least monthly throughout.

Heart-related cautions. Patients with heart failure, recent heart attack, cardiovascular disease, or irregular heart rhythm need close monitoring, since raised blood pressure and low potassium can worsen those conditions. Safety has not been established in patients with a left ventricular ejection fraction below 50% or with moderate to severe heart failure, because they were excluded from the trials. Heart failure occurred in 2.6% of patients on abiraterone versus 0.9% on placebo. QT prolongation and Torsades de Pointes (dangerous heart rhythms) have been reported after marketing, mainly in patients who developed low potassium.

Adrenal insufficiency. Reported in 0.3% of patients. Occurs particularly when prednisone is interrupted or reduced, or during infection or physical stress. Steroid doses may need to be increased before, during, and after stressful situations, under medical supervision.

Do not combine with radium-223. In the ERA-223 trial, combining abiraterone plus prednisone with radium-223 dichloride produced markedly more fractures (28.6% versus 11.4%) and more deaths (38.5% versus 35.5%). This combination is not recommended outside a clinical trial.

Harm to an unborn child. Abiraterone can cause fetal harm and pregnancy loss. It is not used in women. Men with female partners who could become pregnant should use effective contraception during treatment and for 3 weeks after the final dose.

Handling precaution for the household. Women who are pregnant or may become pregnant should not handle these tablets without gloves. In practice, keep the bottle in a place where only the patient handles it.

Severe low blood sugar. Reported in patients with existing diabetes who also take pioglitazone or repaglinide. Blood sugar should be monitored more closely, and diabetes medication doses may need adjusting.

Fertility. Abiraterone may impair fertility in men. Discuss this with your oncologist before starting if it is a concern.

Abiraterone Side Effects

Common (10% or more): fatigue, joint pain, high blood pressure, nausea, swelling of the legs or feet, low potassium, hot flushes, diarrhoea, vomiting, chest or sinus infections, cough, and headache.

Common laboratory changes (more than 20%): low red blood cell count, raised alkaline phosphatase, raised triglycerides and cholesterol, low lymphocyte count, and raised blood sugar.

Reported after the drug reached market: lung inflammation not caused by infection, muscle breakdown (rhabdomyolysis), severe liver injury, dangerous heart rhythms, and severe allergic reactions including difficulty swallowing or breathing and swelling of the face, lips, tongue, or throat. Seek emergency care for any of those allergic symptoms.

This is not a complete list. Report new or worsening symptoms to your treating physician rather than adjusting the dose yourself.

Drug Interactions

Medicines that speed up abiraterone’s breakdown (strong CYP3A4 inducers). These include phenytoin, carbamazepine, phenobarbital, rifampin, rifabutin, and rifapentine. Rifampin reduced abiraterone levels by 55% in a dedicated study — enough to undermine treatment. Avoid where possible; if unavoidable, the oncologist increases dosing frequency during the overlap period.

Medicines abiraterone affects (CYP2D6 substrates). Abiraterone raises blood levels of some other drugs. Avoid combining it with CYP2D6 substrates that have a narrow safety margin, such as thioridazine. Worth knowing for everyday life: abiraterone increased levels of dextromethorphan, the active ingredient in many over-the-counter cough syrups, by nearly threefold. Check with your pharmacist before buying cough or cold remedies.

Pioglitazone and repaglinide. Abiraterone raised pioglitazone exposure by 46%, which connects to the severe low-blood-sugar warning above.

Spironolactone was not permitted during the clinical trials. Tell your oncologist about every medicine, vitamin, and herbal supplement you take, including anything prescribed by a different doctor.

Storage

Store at 20°C to 25°C (68°F to 77°F); brief excursions between 15°C and 30°C are acceptable. Keep out of reach of children, and out of reach of anyone who is or may become pregnant.

Abiraxen vs Zytiga: How This Generic Zytiga Alternative Compares

Provided for orientation only. This is not a claim of bioequivalence, and Abiraxen is not represented as an FDA-approved product.

Frequently Asked Questions