Ztiga – Abiraterone

Dosing

1,000 mg once daily (4 pills daily) in combination with prednisone 5 mg twice daily.

Abiraterone acetate is available in different tablet formulations; use caution when selecting dosage form as dosing and food effects vary between products. The formulations are NOT interchangeable; do not substitute between formulations.

Administration

Administer abiraterone (Zytiga) orally on an empty stomach, at least 1 hour before and 2 hours after food. No food should be consumed for at least 2 hours before or for at least 1 hour after the abiraterone (Zytiga) dose.

Side Effects

Hypertension, hot flashes, weakness or feeling more tired than usual, joint pain or swelling in your legs or feet, heartburn, cold like symptoms, diarrhea, headaches.

Missed Dose

If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. If you miss more than one dose, talk to your doctor right away.

Reproductive Considerations

Male patients with female partners of reproductive potential should use effective contraception during treatment and for 3 weeks after the last abiraterone dose.

Monitoring

CBC w diff, CMP (baseline, every 4-6 weeks after initiation for 3 months, and every three months thereafter).

PSA every 3 months and as clinically indicated.

Mechanism of Action

Abiraterone selectively and irreversibly inhibits CYP17, an enzyme required for androgen biosynthesis which is expressed in testicular, adrenal, and prostatic tumor tissues. Inhibits the formation of the testosterone precursors dehydroepiandrosterone (DHEA) and androstenedione.

In layman’s terms: This medication is an anti-androgen (anti-testosterone). When testosterone binds to an androgen receptor, it causes the tumor cells to grow. You are taking this medication to block the effects of testosterone by slowing down the growth and spread of prostate cancer. As a result, the prostate tumor may stop growing, and the cancer cells die

Storage

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Other Considerations

Be sure to let other prescribers know that you are taking this medication. This drug may interact with other drugs prescribed; such as diuretics, and drugs used to treat seizures. You may be at a higher risk for hypertension; your potassium or magnesium levels may change, and routine lab results may come back irregular.

Notify MD with any new or worrisome side effects.