Abiraterone


Concise Prescribing Info
Indications/Uses
Metastatic, castration-resistant prostate cancer.
Dosage/Direction for Use
Adult : PO 1 g once daily, w/ prednisone or prednisolone.
Dosage Details
Oral
Prostate cancer
Adult: Metastatic, castration-resistant prostate cancer: 1 g once daily, in combination w/ prednisone or prednisolone.
Hepatic Impairment
Moderate (Child-Pugh Class B): 250 mg once daily; permanently discontinue if ALT/AST reaches >5 times the upper limit of normal (ULN) or total bilirubin >3 times ULN during treatment. Severe (Child-Pugh Class C): Contraindicated.
Administration
Should be taken on an empty stomach. Take at least 1 hr before or 2 hr after meals. Swallow whole, do not chew/crush.
Contraindications
Severe hepatic impairment (Child-Pugh Class C). Pregnancy and lactation.
Special Precautions
Patient w/ ventricular arrhythmia, heart failure, recent MI, severe or unstable angina, DM, history of CV disease. Moderate hepatic and severe renal impairment.
Adverse Reactions
Significant: Adrenocortical insufficiency, mineralocorticoid excess (often leads to fluid retention, hypokalaemia, HTN, and cardiac failure), hyperglycaemia, anaemia, myopathy, rhabdomyolysis, decreased bone density, sexual dysfunction.
Nervous: Fatigue.
CV: Angina pectoris, arrhythmias (e.g. AF, tachycardia), chest pain, oedema, hot flush.
GI: Diarrhoea, dyspepsia.
Resp: Upper resp tract infection, cough.
Hepatic: Increased transaminase and bilirubin levels.
Genitourinary: Nocturia, urinary frequency, UTI.
Endocrine: Hypertriglyceridaemia, hypophosphataemia.
Musculoskeletal: Muscular discomfort, joint swelling, fractures.
Immunologic: Sepsis.
Dermatologic: Rash.
Potentially Fatal: Hepatotoxicity (e.g. acute liver failure, fulminant hepatitis).
MonitoringParameters
Monitor BP, serum K level, and fluid balance prior to and at least mthly during therapy; LFT prior to therapy, then 2 wkly on the 1st 3 mth, then mthly thereafter. Monitor signs and symptoms of adrenocorticoid insufficiency.
Drug Interactions
Increased risk of hypokalaemia w/ K-lowering drugs (e.g. thiazide diuretics). Risk of tumour progression w/ spironolactone. Decreased exposure w/ strong CYP3A4 inducers (e.g. rifampicin). Increased plasma concentration w/ potent CYP3A4 inhibitors e.g. ketoconazole. Increased risk of QT prolongation w/ antiarrhythmics (e.g. quinidine, amiodarone), antipsychotics, moxifloxacin, methadone. May increase exposure to drugs that are metabolised or activated by CYP2D6 (e. g. desipramine, venlafaxine, metoprolol), esp those w/ narrow therapeutic index.
Food Interaction
Increased absorption w/ food. Decreased absorption w/ St John’s wort. Increased plasma concentration w/ grapefruit or grapefruit juice.
Action
Description: Abiraterone suppresses testosterone production through selective and irreversible inhibition of 17 α-hydroxylase/C17, 20-lyase (CYP17), an enzyme required for androgen biosynthesis in testicular, adrenal, and prostatic tumour tissues.
Pharmacokinetics:
Absorption: Increased absorption w/ food. Time to peak plasma concentration: Approx 2 hr.
Distribution: Plasma protein binding: >99%, to albumin and α1-acid glycoprotein.
Metabolism: Metabolised in the liver via hydroxylation, oxidation, and sulfation by CYP3A4 and sulfotransferase (SULT2A1) enzymes, forming 2 major inactive metabolites, abiraterone sulfate and N-oxide abiraterone sulfate.
Excretion: Via faeces (88%) and urine (approx 5%). Terminal elimination half-life: Approx 15 hr.
Chemical Structure

Click on icon to see table/diagram/image
Storage
Store between 20-25°C.
ATC Classification
L02BX03 - abiraterone ; Belongs to the class of other hormone antagonists and related agents. Used in the treatment of metastatic castration-resistant prostate cancer.
Disclaimer: This information is independently developed by MIMS based on Abiraterone from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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