Drug Detail:Zytiga (Abiraterone [ a-bir-a-te-rone ])
Generic Name: abiraterone acetate 250mg
Dosage Form: tablet
Drug Class: Miscellaneous antineoplastics
Recommended Dose for Metastatic CRPC
The recommended dose of ZYTIGA is 1,000 mg (two 500 mg tablets or four 250 mg tablets) orally once daily with prednisone 5 mg orally twice daily.
Recommended Dose for Metastatic High-risk CSPC
The recommended dose of ZYTIGA is 1,000 mg (two 500 mg tablets or four 250 mg tablets) orally once daily with prednisone 5 mg administered orally once daily.
Important Administration Instructions
Patients receiving ZYTIGA should also receive a gonadotropin-releasing hormone (GnRH) analog concurrently or should have had bilateral orchiectomy.
ZYTIGA tablets must be taken as a single dose once daily on an empty stomach. Do not eat food 2 hours before and 1 hour after taking ZYTIGA. The tablets must be swallowed whole with water. Do not crush or chew tablets.
Dose Modification Guidelines in Hepatic Impairment and Hepatotoxicity
Hepatic Impairment
In patients with baseline moderate hepatic impairment (Child-Pugh Class B), reduce the recommended dose of ZYTIGA to 250 mg once daily. In patients with moderate hepatic impairment monitor ALT, AST, and bilirubin prior to the start of treatment, every week for the first month, every two weeks for the following two months of treatment and monthly thereafter. If elevations in ALT and/or AST greater than 5 × upper limit of normal (ULN) or total bilirubin greater than 3 × ULN occur in patients with baseline moderate hepatic impairment, discontinue ZYTIGA and do not re-treat patients with ZYTIGA [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)].
Do not use ZYTIGA in patients with baseline severe hepatic impairment (Child-Pugh Class C).
Hepatotoxicity
For patients who develop hepatotoxicity during treatment with ZYTIGA (ALT and/or AST greater than 5 × ULN or total bilirubin greater than 3 × ULN), interrupt treatment with ZYTIGA [see Warnings and Precautions (5.3)]. Treatment may be restarted at a reduced dose of 750 mg once daily following return of liver function tests to the patient's baseline or to AST and ALT less than or equal to 2.5 × ULN and total bilirubin less than or equal to 1.5 × ULN. For patients who resume treatment, monitor serum transaminases and bilirubin at a minimum of every two weeks for three months and monthly thereafter.
If hepatotoxicity recurs at the dose of 750 mg once daily, re-treatment may be restarted at a reduced dose of 500 mg once daily following return of liver function tests to the patient's baseline or to AST and ALT less than or equal to 2.5 × ULN and total bilirubin less than or equal to 1.5 × ULN.
If hepatotoxicity recurs at the reduced dose of 500 mg once daily, discontinue treatment with ZYTIGA.
Permanently discontinue ZYTIGA for patients who develop a concurrent elevation of ALT greater than 3 × ULN and total bilirubin greater than 2 × ULN in the absence of biliary obstruction or other causes responsible for the concurrent elevation [see Warnings and Precautions (5.3)].
Dose Modification Guidelines for Strong CYP3A4 Inducers
Avoid concomitant strong CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital) during ZYTIGA treatment.
If a strong CYP3A4 inducer must be co-administered, increase the ZYTIGA dosing frequency to twice a day only during the co-administration period (e.g., from 1,000 mg once daily to 1,000 mg twice a day). Reduce the dose back to the previous dose and frequency, if the concomitant strong CYP3A4 inducer is discontinued [see Drug Interactions (7.1) and Clinical Pharmacology (12.3)].
