NILUTAMIDE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NILUTAMIDE (NILUTAMIDE).
Nonsteroidal antiandrogen that competitively inhibits androgen binding to androgen receptors, blocking androgen action in target tissues.
| Metabolism | Hepatic via multiple pathways including cytochrome P450; active metabolites: nilutamide and metabolites. |
| Excretion | Nilutamide is extensively metabolized; less than 2% of the dose is excreted unchanged in urine. The majority of metabolites (approximately 70%) are excreted renally, with the remainder (about 30%) eliminated in feces via biliary excretion. |
| Half-life | The terminal elimination half-life is approximately 38–56 hours (mean ~49 hours), allowing once-daily dosing. Steady-state is achieved after about 7–10 days. |
| Protein binding | ≥98% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 0.7–1.2 L/kg, indicating extensive tissue distribution. |
| Bioavailability | 82–96% following oral administration (well absorbed); food may slightly increase absorption. |
| Onset of Action | Oral administration: Clinical effects (androgen receptor blockade) begin within a few days, but full therapeutic response may take 2–4 weeks due to gradual suppression of androgen-dependent growth. |
| Duration of Action | With once-daily dosing, androgen receptor blockade is maintained throughout the 24-hour dosing interval. The drug's long half-life provides sustained action; after discontinuation, effects persist for several days. |
300 mg orally once daily
| Dosage form | TABLET |
| Renal impairment | No adjustment required for GFR ≥30 mL/min; not recommended for GFR <30 mL/min due to lack of data |
| Liver impairment | Contraindicated in Child-Pugh Class C; caution in Child-Pugh Class B (reduce dose to 150 mg once daily) |
| Pediatric use | Safety and efficacy not established; no standard pediatric dosing |
| Geriatric use | No specific dose adjustment; monitor for increased risk of interstitial pneumonitis and hepatic toxicity |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NILUTAMIDE (NILUTAMIDE).
| Breastfeeding | It is unknown whether nilutamide is excreted in human breast milk. Due to the potential for serious adverse reactions in the breastfeeding infant, including antiandrogenic effects, breastfeeding is contraindicated during nilutamide therapy and for at least 5 months after the last dose. No M/P ratio is available. |
| Teratogenic Risk | NILUTAMIDE is contraindicated in pregnancy. Based on its antiandrogenic mechanism, there is a high risk of feminization of male fetuses, including ambiguous genitalia and hypospadias, particularly during the first trimester when sexual differentiation occurs. Animal studies have shown teratogenic effects at doses lower than human therapeutic doses. Use in women of childbearing potential requires effective contraception before, during, and for at least 5 months after treatment. |
■ FDA Black Box Warning
None
| Serious Effects |
Severe hepatic impairment (Child-Pugh class C), severe respiratory insufficiency, hypersensitivity to nilutamide.
| Precautions | Interstitial pneumonitis (risk increased in Asian patients), hepatotoxicity, alcohol intolerance (disulfiram-like reaction), visual disturbances (impaired adaptation to dark), cardiovascular effects (hypertension), anemia. |
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| Fetal Monitoring | Pregnancy testing should be performed before initiating nilutamide in women of childbearing potential. If used inadvertently during pregnancy, monitor fetal development with ultrasound to detect signs of feminization in male fetuses. Monitor maternal liver function tests, pulmonary status (interstitial pneumonitis), and ocular symptoms (visual disturbances) as nilutamide can cause hepatotoxicity, interstitial pneumonitis, and optic neuritis. |
| Fertility Effects | Nilutamide is an antiandrogen that may impair spermatogenesis and reduce fertility in males. In females, it may disrupt ovulation due to hormonal antagonism. Use may lead to reversible infertility in both sexes during treatment. |