Zytiga Generic Name & Formulations
Abiraterone acetate 250mg, 500mg; tabs.
Tabs 250mg—120; 500mg—60
In combination with prednisone for the treatment of metastatic castration-resistant prostate cancer (CRPC) and metastatic high-risk castration-sensitive prostate cancer (CSPC).
Zytiga Dosage and Administration
Take on an empty stomach. Swallow whole with water. 1g once daily (in combination with oral prednisone 5mg twice daily [CRPC] or 5mg once daily [CSPC]). Also give concurrent GnRH analog or patient should have had bilateral orchiectomy. Baseline moderate hepatic impairment (Child-Pugh Class B): 250mg once daily; monitor closely; discontinue if ALT/AST >5xULN or total bilirubin >3xULN. If concomitant strong CYP3A4 inducer necessary, increase abiraterone dose frequency to twice daily during co-administration period (eg, from 1g once daily to 1g twice daily); reduce back to previous dose/frequency when CYP3A4 inducer is discontinued.
Zytiga Boxed Warnings
Risk of mineralocorticoid excess; monitor BP, serum potassium, fluid retention at least monthly. Control hypertension and correct hypokalemia before and during treatment. Heart failure, recent MI, cardiovascular disease, ventricular arrhythmias; monitor closely. Monitor for adrenocortical insufficiency. Stress (may need higher corticosteroid dose). Monitor LFTs prior to starting treatment, every 2 weeks for the first 3 months, and monthly thereafter. Baseline moderate hepatic impairment (Child-Pugh Class B): monitor LFTs prior to initiation, weekly for the first month, every 2 weeks for the next 2 months, and monthly thereafter. Interrupt and reduce dose if hepatotoxicity (ALT/AST >5×ULN or total bilirubin >3×ULN) occurs; see full labeling. Permanently discontinue if concurrent ALT elevation >3×ULN and total bilirubin >2×ULN develops without biliary obstruction or other causes of elevation. Baseline severe hepatic impairment (Child-Pugh Class C): not recommended. Preexisting diabetes (esp. those taking thiazolidinediones-containing products). Embryo-fetal toxicity. Advise males with female partners of reproductive potential to use effective contraception during therapy and for 3 weeks after last dose. Pregnancy. Nursing mothers: not established.
Increased risk of fracture and death when concomitant abiraterone plus prednisone/prednisolone with radium Ra 223 dichloride; not recommended. Antagonized by strong CYP3A4 inducers (eg, phenytoin, carbamazepine, rifampin, rifabutin, rifapentin, phenobarbital); avoid (or see Adult). Potentiates CYP2D6 (eg, dextromethorphan) or CYP2C8 substrates (eg, pioglitazone); monitor closely for toxicity. Avoid concomitant CYP2D6 substrates with narrow therapeutic index (eg, thioridazine); if no alternatives, consider dose reduction of substrate.
Zytiga Adverse Reactions
Fatigue, arthralgia, hypertension, nausea, edema, hypokalemia, hot flush, diarrhea, vomiting, upper respiratory infection, cough, headache, anemia, elevated LFTs, dyslipidemia, lymphopenia, hyperglycemia; hypoglycemia, hepatotoxicity (may be severe).
Zytiga Clinical Trials
Pregnant women and those of childbearing potential should not handle Zytiga tablets without protection (eg, gloves). Partners must use appropriate barrier contraception.
Zytiga Patient Counseling