abiraterone acetate + niraparib tosylate monohydrate: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
abiraterone acetate + niraparib tosylate monohydrate: clinical details
Prescribing considerations
- Confirm BRCA1 or BRCA2 mutation using a validated germline or somatic test.
- Treatment must be initiated and supervised by a prostate-cancer specialist and accompanied by prednisone or prednisolone.
- Optimise hypertension, potassium, fluid status, cardiac function and other cardiovascular risk factors before treatment.
- Assess hepatic and renal function, previous thrombosis, baseline cytopenias, diabetes, fracture risk and interacting medicines.
- Ensure corticosteroid cover is considered during significant physiological stress and avoid abrupt unsupervised corticosteroid withdrawal.
Contraindications and cautions
- Hypersensitivity to an active substance or excipient
- Women who are or may become pregnant
- Severe hepatic impairment
- Concurrent treatment with radium-223
Monitoring
- Full blood count frequently at initiation, then at progressively longer intervals if stable.
- Blood pressure at least weekly initially, with ongoing monitoring thereafter.
- Potassium, fluid retention, weight and signs of cardiac failure.
- Liver aminotransferases and bilirubin before treatment and regularly during therapy.
- Blood glucose in people with diabetes, particularly with pioglitazone or repaglinide.
- Clinical signs of infection, pulmonary embolism, PRES, persistent cytopenia, MDS or AML.
- Renal function and adverse effects closely in severe renal impairment.
Clinical pharmacology
Niraparib inhibits PARP-1 and PARP-2, promoting unrepaired DNA damage and cancer-cell death. Abiraterone acetate is a prodrug of the CYP17 inhibitor abiraterone, reducing androgen synthesis but increasing mineralocorticoid production; concomitant corticosteroid suppresses ACTH-driven mineralocorticoid effects.
Formulation and product differences
- The selected film-coated tablet is the regular-strength presentation; a lower-strength presentation is available for toxicity-related reduction.
- The lower-strength presentation produces higher abiraterone exposure than an equivalent combination of the separate components, so product-specific monitoring instructions apply after switching.
- Tablets contain lactose and are essentially sodium-free; they must be swallowed whole.
abiraterone acetate + niraparib tosylate monohydrate preparations and strengths
Tablet
Route: Oral
Strengths: 50 mg + 500 mg, 100 mg + 500 mg
abiraterone acetate + niraparib tosylate monohydrate interactions
The oncology team should review all medicines, supplements and herbal products before and during treatment.
Strong CYP3A4 inducers, including carbamazepine, phenytoin, rifampicin, phenobarbital and St John’s wort
These may reduce abiraterone exposure and should generally be avoided unless no alternative exists.
CYP2D6 substrates, including flecainide, propafenone, metoprolol, venlafaxine, codeine and tramadol
Abiraterone can alter exposure or activation, particularly where the interacting medicine has a narrow therapeutic index.
Pioglitazone or repaglinide
Exposure may change and hypoglycaemia has occurred; monitor glucose and adverse effects closely.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.