apalutamide: clinical use

Prescribing considerations

• Treatment should be initiated and supervised by a clinician experienced in prostate-cancer treatment.
• Reconcile all prescribed, non-prescribed and complementary products because clinically important loss of co-medication efficacy is possible.
• Assess seizure predisposition, fall and fracture risk, cardiovascular status and QT-risk factors before treatment.
• Evidence is limited in severe renal impairment; severe hepatic impairment substantially alters exposure.

Contraindications and cautions

• Hypersensitivity to apalutamide or an excipient.
• Women who are pregnant or may become pregnant.

Monitoring

• Blood pressure and cardiovascular or cerebrovascular symptoms.
• Falls, fracture risk and bone health.
• Skin rash, particularly blistering, mucosal or systemic features.
• New or worsening respiratory symptoms suggesting interstitial lung disease.
• Thyroid function, especially in patients receiving thyroid replacement.
• Effectiveness or concentrations of susceptible interacting medicines; INR if warfarin use is unavoidable.
• Seizures and medicines that lower the seizure threshold.

Clinical pharmacology

Apalutamide is a selective androgen-receptor antagonist without agonist activity. It blocks receptor nuclear translocation, DNA binding and androgen-mediated transcription. Its active N-desmethyl metabolite contributes to activity; metabolism involves CYP2C8 and CYP3A4, while apalutamide strongly induces several enzymes and transporters.

Formulation and product differences

• The selected product is a large, oval, bluish-grey film-coated tablet.
• It must not be crushed or split, but supported dispersion in non-fizzy water and soft food or drink is possible.
• Administration through a suitable nasogastric tube is supported by product-specific instructions.
• Bottle and wallet-blister presentations may be available; store in the original packaging to protect from moisture.

Tablet

Route: Oral

Strengths: 60 mg, 240 mg