Zyterone Tablet 250 mg

Indications

Abiraterone Acetate is a hormone-based cancer medicine used to treat prostate cancer in men. It is used for metastatic prostate cancer (cancer that has spread) that no longer responds to standard hormone treatment (castration-resistant), and for newly diagnosed high-risk metastatic prostate cancer that is still sensitive to hormone therapy. It is always given together with a steroid, usually Prednisolone or Prednisone, and with ongoing testosterone-lowering treatment.

How It Works

Prostate cancer cells usually need male hormones (androgens) such as testosterone to grow. Abiraterone blocks an enzyme called CYP17, which the testes, adrenal glands and the tumour itself use to make androgens. By shutting down androgen production in all these places, it starves the cancer of the hormones that drive it. The added steroid replaces cortisol and prevents side effects caused by changes in other adrenal hormones.

Dosage and Administration

Take exactly as prescribed by your cancer specialist, together with the prescribed steroid. Abiraterone is usually taken once a day on an empty stomach, at least 1 hour before or 2 hours after food, swallowed whole with water. Taking it with food greatly increases absorption and side effects. Do not stop the steroid suddenly. Your doctor may change the dose if you have liver problems.

Interactions

• Strong CYP3A4 inducers such as Rifampicin, Carbamazepine, Phenytoin and Phenobarbital can reduce its effect.
• It can raise levels of medicines broken down by CYP2D6, such as Dextromethorphan, Metoprolol, Flecainide and some antidepressants and antipsychotics.
• Use with Radium-223 is not recommended.
• Medicines that lower potassium, such as some diuretics, need extra monitoring.

Contraindications

• Allergy to Abiraterone or any ingredient
• Severe liver disease
• Women, especially those who are or may become pregnant

Side Effects

• Swelling of the legs and feet (fluid retention)
• Low blood potassium, which can cause muscle weakness or cramps
• High blood pressure
• Hot flushes, tiredness, joint pain
• Raised liver enzymes
• Urinary tract infection, indigestion, diarrhoea

Get urgent medical help if you notice yellow skin or eyes, dark urine, severe nausea or pain in the upper right abdomen (possible liver injury), a fast or irregular heartbeat, chest pain, severe muscle weakness, sudden breathlessness or marked swelling, or signs of adrenal crisis such as severe weakness, dizziness, vomiting and confusion, especially during illness or stress.

Pregnancy and Lactation

Abiraterone is not for use in women and can harm an unborn baby. Pregnant women or women who may become pregnant should not handle the tablets without gloves. Men taking it should use a condom and another effective contraceptive method if their partner could become pregnant, during treatment and for 3 weeks afterwards.

Precautions and Warnings

• Liver tests are checked before treatment, every 2 weeks for the first 3 months, then monthly.
• Blood pressure, potassium and fluid levels are checked regularly.
• Use with care in heart disease, heart failure or recent heart attack.
• Tell your doctor before surgery or if you have an infection or severe stress, as the steroid dose may need adjusting.
• It can lower bone density; your doctor may advise calcium, vitamin D or bone-protecting treatment.

Overdose

There is no specific antidote. Overdose may increase side effects such as high blood pressure, low potassium and fluid retention. Contact your doctor or go to hospital; treatment is supportive with monitoring of the heart and liver.

Therapeutic Class

Antineoplastic hormone therapy, androgen biosynthesis (CYP17) inhibitor

Storage

Store below 30°C in a dry place, in the original pack, away from light and out of the reach of children.