Generic Name

Apalutamide

---

Classification

FDA Approved Indications

• Non-metastatic castration-resistant prostate cancer (nmCRPC)

Mechanism of Action

Apalutamide inhibits androgen receptor signaling by binding to the ligand-binding domain of the androgen receptor, thus preventing androgen-induced nuclear translocation, DNA binding, and transcription of androgen-responsive genes.

Dosage and Administration

Adult: 240 mg orally once daily, with or without food.

Pediatric: Not approved for pediatric use.

Geriatric: No specific dosage adjustments, but monitor closely due to comorbidities.

Renal Impairment: No dosage adjustment recommended for mild to moderate impairment; limited data for severe impairment.

Hepatic Impairment: No specific dosage adjustment; use with caution.

Pharmacokinetics

Absorption: Rapid, with peak plasma concentrations in approximately 2 hours.

Distribution: Bound approximately 96% to plasma proteins.

Metabolism: Primarily hepatic via CYP2C8 and CYP3A4; also metabolized by glucuronidation.

Excretion: Mainly fecal (about 80%), with some renal excretion.

Half Life: Approximately 3 days (long half-life).

Contraindications

• Hypersensitivity to apalutamide or any components of the formulation.

Precautions

• Seizure risk, particularly in patients with a history of seizures or predisposition.
• Monitoring for falls and fractures, as these may be increased.
• Potential for drug interactions affecting CYP enzymes.

Adverse Reactions - Common

• Fatigue (Common)
• rash (Common)
• Diarrhea (Common)
• Hot flashes (Common)
• Hypertension (Common)

Adverse Reactions - Serious

• Seizures (Less common)
• Falls and fractures (Less common)
• Hypertension requiring treatment (Less common)

Drug-Drug Interactions

• CYP2C8 or CYP3A4 inhibitors or inducers may affect apalutamide levels.
• Anticoagulants: increased bleeding risk.

Drug-Food Interactions

• No specific food interactions identified.

Drug-Herb Interactions

• Caution with herbal supplements that may affect CYP enzymes or increase seizure risk.

Nursing Implications

Patient/Family Teaching

• Do not discontinue medication without consulting your healthcare provider.
• Report any signs of seizures, falls, or fractures immediately.
• Avoid activities that may increase fall risk.
• Inform about potential skin rash and when to seek medical attention.

Special Considerations

Black Box Warnings:

• Risk of seizures. Patients with a history of seizures should be carefully evaluated before starting therapy.

Genetic Factors: No specific genetic testing required.

Lab Test Interference: May affect androgen and testosterone levels.

Overdose Management

Signs/Symptoms: Dizziness, confusion, seizures, or other neurological symptoms.

Treatment: Supportive care; consider use of activated charcoal if ingestion was recent; seizure management as per standard protocols.

Storage and Handling

Storage: Store at room temperature between 20°C to 25°C (68°F to 77°F).

Stability: Stable for up to 3 years when stored properly.