abiraterone acetate: clinical use

Prescribing considerations

• Prescribe within specialist prostate-cancer care and confirm appropriate corticosteroid co-treatment and continued medical castration where relevant.
• Correct hypertension, hypokalaemia and fluid retention before treatment; assess cardiac function when heart-failure risk is significant.
• Review hepatic function, cardiovascular disease, diabetes, fracture risk and medicines associated with myopathy or QT prolongation.
• Plan corticosteroid cover during unusual physiological stress and monitor for adrenal insufficiency if the corticosteroid is reduced or withdrawn.

Contraindications and cautions

• Hypersensitivity to abiraterone acetate or an excipient.
• Women who are or may be pregnant.
• Severe hepatic impairment.
• Combination of abiraterone acetate plus prednisone or prednisolone with radium-223.

Monitoring

• Liver transaminases before and regularly during treatment, with prompt testing if hepatotoxicity is suspected.
• Blood pressure, serum potassium, weight, peripheral oedema and symptoms of cardiac failure.
• Blood glucose in people with diabetes, particularly when using pioglitazone or repaglinide.
• Clinical response, including PSA where appropriate, and bone health according to individual risk.

Clinical pharmacology

Abiraterone acetate is a prodrug rapidly converted to abiraterone, a selective CYP17 inhibitor. It suppresses androgen synthesis in testicular, adrenal and prostate tumour tissues while increasing upstream mineralocorticoid production. It inhibits CYP2D6 and CYP2C8 and is principally metabolised in the liver.

Formulation and product differences

• The selected product is a film-coated tablet that must be swallowed whole and taken without food.
• It contains lactose and is described as essentially sodium-free.
• Tablet appearance, excipients and pack configuration can differ between manufacturers; verify the supplied product information.

Tablet

Route: Oral

Strengths: 250 mg, 500 mg, 1000 mg