enzalutamide: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
enzalutamide: clinical details
Prescribing considerations
- Treatment should be initiated and supervised by a prostate-cancer specialist.
- Reconcile all medicines because clinically important enzyme induction develops gradually and can persist for a month or longer after withdrawal.
- Assess seizure risk, cardiovascular disease, blood pressure, QT-prolongation risk, falls and fracture risk.
- Use caution in severe renal impairment or end-stage renal disease; clinical experience is limited.
- Severe hepatic impairment may prolong elimination and delay the onset or offset of enzyme induction.
Contraindications and cautions
- Hypersensitivity to enzalutamide or an excipient.
- Women who are pregnant or may become pregnant.
Monitoring
- Cancer response, including PSA and clinical or radiological progression as appropriate.
- Blood pressure before and during treatment.
- Neurological symptoms, cognition, falls and fractures.
- Skin reactions and hypersensitivity.
- Cardiovascular symptoms and QT risk where clinically relevant.
- Efficacy or concentrations of interacting medicines, including additional INR checks if a coumarin anticoagulant cannot be avoided.
Clinical pharmacology
Enzalutamide and its active N-desmethyl metabolite inhibit androgen-receptor signalling. It is mainly metabolised by CYP2C8, with a smaller CYP3A4 contribution, has a long terminal half-life and induces CYP3A4, CYP2C9 and CYP2C19.
Formulation and product differences
- The selected Great Britain product is a film-coated tablet that must remain intact.
- Swallowing difficulty and choking were reported more often with the former, larger soft-capsule formulation.
- Women who are or may become pregnant should not handle broken or damaged tablets without protective gloves.
enzalutamide preparations and strengths
Tablet
Route: Oral
Strengths: 40 mg
enzalutamide interactions
Enzalutamide affects several drug-metabolising enzymes and transporters. The full medication list should be reviewed before starting or stopping it.
Warfarin and acenocoumarol
Enzalutamide may reduce anticoagulant exposure; avoid where possible or arrange additional INR monitoring.
Gemfibrozil and other strong CYP2C8 inhibitors
These can substantially increase enzalutamide exposure and should generally be avoided or managed by the specialist.
CYP3A4, CYP2C9 or CYP2C19 substrates
Medicines including some statins, opioids, antiepileptics, corticosteroids and immunosuppressants may become less effective.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.