Mechanism of Action
- Second-generation androgen receptor (AR) antagonist.
- Binds AR and prevents nuclear translocation, DNA binding, and transcription of AR-dependent genes.
- Inhibits prostate cancer cell growth driven by androgen signaling.
Indications
- Non-metastatic Castration-Resistant Prostate Cancer (nmCRPC)
- Metastatic Castration-Sensitive Prostate Cancer (mCSPC) in combination with ADT
Dosing
- 240 mg PO once daily (four × 60 mg tablets)
- With or without food
- Continue ADT during therapy
Adverse Effects & Monitoring
- Common: fatigue, rash, hypothyroidism, arthralgia, falls
- Serious but less common: fractures, seizures (rare)
- Laboratory monitoring: TSH (hypothyroidism), LFTs (rare hepatotoxicity)
- Monitor blood pressure and bone health
Pharmacist Considerations
- Oral adherence is crucial; missed doses may reduce efficacy.
- Drug interactions: metabolized via CYP2C8 and CYP3A4; strong inducers/inhibitors may affect plasma levels.
- Educate patients on fall precautions, rash management, and reporting thyroid symptoms.
- Used to delay metastasis in nmCRPC and prolong survival in mCSPC.