Indications
Niraparib is used as maintenance treatment in adults whose epithelial ovarian, fallopian tube or primary peritoneal cancer has come back (recurrent) and who have had a complete or partial response to platinum-based chemotherapy.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Niraparib is an inhibitor of the poly (ADP-ribose) polymerase enzymes PARP-1 and PARP-2, which take part in DNA repair. In vitro studies suggest that the cytotoxicity caused by niraparib may involve two things: inhibition of PARP enzymatic activity, and a rise in the formation of PARP-DNA complexes. Together these lead to DNA damage, apoptosis and cell death. The cytotoxic effect of niraparib was greater in tumor cell lines whether or not they had deficiencies in BRCA1/2. Niraparib also slowed tumor growth in mouse xenograft models of human cancer cell lines with BRCA1/2 deficiencies. The same was seen in human patient-derived xenograft tumor models with homologous recombination deficiency, whether the BRCA1/2 was mutated or wild type.
Absorption: The absolute bioavailability of niraparib is approximately 73%. After an oral dose, the peak plasma concentration (Cmax) is reached within 3 hours. A high fat meal (800-1,000 calories, with approximately 50% of the total calories coming from fat) taken together with niraparib did not significantly affect its pharmacokinetics.
Distribution: Niraparib is 83.0% bound to human plasma proteins. The average (±SD) apparent volume of distribution (Vd/F) was 1220 (±1114) L. A population pharmacokinetic analysis gave a Vd/F of 1074 L for niraparib in cancer patients.
Elimination: After multiple daily doses of 300 mg niraparib, the mean half-life (t1/2) is 36 hours. In a population pharmacokinetic analysis, the apparent total clearance (CL/F) of niraparib in cancer patients was 16.2 L/h.
Metabolism: Niraparib is metabolized mainly by carboxylesterases (CEs) into a major inactive metabolite, which then undergoes glucuronidation.
Excretion: A single oral 300 mg dose of radio-labeled niraparib was given. Over 21 days, the average recovery of the administered dose was 47.5% in urine (range 33.4% to 60.2%) and 38.8% in feces (range 28.3% to 47.0%). In pooled samples collected over 6 days, unchanged niraparib made up 11% of the administered dose recovered in urine and 19% of the dose recovered in feces.
Pregnancy & Breastfeeding
Women who could become pregnant should not be pregnant when they start Niraparib, and they should not become pregnant while taking it. A pregnancy test should be done on every woman of childbearing potential before treatment begins. These women must use effective contraception during treatment and for 1 month after the last dose of Niraparib.
Pregnancy: There is little or no data on the use of Niraparib in pregnant women. Animal studies of reproductive and developmental toxicity have not been done. Still, going by how the medicine works, niraparib could harm an embryo or foetus, including embryo-lethal and teratogenic effects, if a pregnant woman takes it. Niraparib should not be used during pregnancy.
Breast-feeding: It isn't known whether niraparib or its metabolites pass into human milk. Breast-feeding is contraindicated while taking Niraparib and for 1 month after the last dose.
Fertility: There are no clinical data on fertility. A reversible reduction of spermatogenesis was seen in rats and dogs.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.