Zytiga Dosage/Direction for Use

This medicinal product should be prescribed by an appropriate healthcare professional.
Posology: The recommended dose is 1,000 mg (two 500 mg tablets) as a single daily dose that must not be taken with food (see Method of administration as follows). Taking the tablets with food increases systemic exposure to abiraterone (see Interactions and Pharmacology: Pharmacokinetics under Actions).
Dosage of prednisone or prednisolone: For mHSPC, ZYTIGA is used with 5 mg prednisone or prednisolone daily.
For mCRPC, ZYTIGA is used with 10 mg prednisone or prednisolone daily.
Medical castration with luteinising hormone releasing hormone (LHRH) analogue should be continued during treatment in patients not surgically castrated.
Recommended monitoring: Serum transaminases should be measured prior to starting treatment, every two weeks for the first three months of treatment and monthly thereafter. Blood pressure, serum potassium and fluid retention should be monitored monthly. However, patients with a significant risk for congestive heart failure should be monitored every 2 weeks for the first three months of treatment and monthly thereafter (see Precautions).
In patients with pre-existing hypokalaemia or those that develop hypokalaemia whilst being treated with ZYTIGA, consider maintaining the patient's potassium level at ≥4.0 mM.
For patients who develop Grade ≥3 toxicities including hypertension, hypokalaemia, oedema and other non-mineralocorticoid toxicities, treatment should be withheld and appropriate medical management should be instituted. Treatment with ZYTIGA should not be reinitiated until symptoms of the toxicity have resolved to Grade 1 or baseline.
In the event of a missed daily dose of either ZYTIGA, prednisone or prednisolone, treatment should be resumed the following day with the usual daily dose.
Hepatotoxicity: For patients who develop hepatotoxicity during treatment (alanine aminotransferase [ALT] increases or aspartate aminotransferase [AST] increases above 5 times the upper limit of normal [ULN]), treatment should be withheld immediately (see Precautions). Re-treatment following return of liver function tests to the patient's baseline may be given at a reduced dose of 500 mg (one tablet) once daily. For patients being re-treated, serum transaminases should be monitored at a minimum of every two weeks for three months and monthly thereafter. If hepatotoxicity recurs at the reduced dose of 500 mg daily, treatment should be discontinued.
If patients develop severe hepatotoxicity (ALT or AST 20 times the ULN) anytime while on therapy, treatment should be discontinued and patients should not be re-treated.
Hepatic impairment: No dose adjustment is necessary for patients with pre-existing mild hepatic impairment, Child-Pugh Class A.
Moderate hepatic impairment (Child-Pugh Class B) has been shown to increase the systemic exposure to abiraterone by approximately four-fold following single oral doses of abiraterone acetate 1,000 mg (see Pharmacology: Pharmacokinetics under Actions). There are no data on the clinical safety and efficacy of multiple doses of abiraterone acetate when administered to patients with moderate or severe hepatic impairment (Child-Pugh Class B or C). No dose adjustment can be predicted. The use of ZYTIGA should be cautiously assessed in patients with moderate hepatic impairment, in whom the benefit clearly should outweigh the possible risk (see Precautions and Pharmacology: Pharmacokinetics under Actions). ZYTIGA should not be used in patients with severe hepatic impairment (see Contraindications, Precautions, and Pharmacology: Pharmacokinetics under Actions).
Renal impairment: No dose adjustment is necessary for patients with renal impairment (see Pharmacology: Pharmacokinetics under Actions). However, there is no clinical experience in patients with prostate cancer and severe renal impairment. Caution is advised in these patients (see Precautions).
Paediatric population: There is no relevant use of ZYTIGA in the paediatric population.
Method of administration: ZYTIGA is for oral use.
The tablets should be taken at least one hour before or at least two hours after eating. These should be swallowed whole with water.