Pharmacology · Antiandrogens and androgen synthesis inhibitors
Enzalutamide !
A second-generation antiandrogen for prostate cancer that blocks the androgen receptor more strongly than older drugs. It can cause falls and, rarely, seizures.
Updated 2026-11-01
No crystal structure with enzalutamide is available. The figure shows bicalutamide, an older antiandrogen, in the same ligand-binding pocket of the human androgen receptor.
Mechanism of action
Enzalutamide is a non-steroidal competitive androgen receptor antagonist with much higher affinity than bicalutamide. It prevents androgens from binding, reducing receptor-driven gene transcription in prostate cancer cells, and prolongs survival in castration-resistant disease.
- Binds the androgen receptor with high affinity
- Androgens cannot bind
- Receptor-driven gene transcription falls
- Prostate cancer growth slows, even when castration-resistant
Pharmacokinetics
- Absorption
- Taken by mouth once a day, with or without food
- Metabolism
- By CYP2C8 and CYP3A4; it is itself a strong inducer of several liver enzymes
- Half-life
- About 6 days; steady state takes about a month
Indications
- Castration-resistant prostate cancer, metastatic or non-metastatic Prostate cancer →
- Metastatic castration-sensitive prostate cancer Prostate cancer →
Adverse effects
Common
- Fatigue and weakness
- Hot flushes
- Back and joint pain
- Hypertension
- Decreased appetite and diarrhoea
- Dizziness and headache
Contraindications
- Not for use in women, especially in pregnancy
Key interactions
- Strong CYP2C8 inhibitors (gemfibrozil)
- Raise enzalutamide levels.
- Strong CYP3A4 inducers (rifampicin)
- Lower enzalutamide levels.
- Substrates of CYP3A4, CYP2C9 and CYP2C19 (for example warfarin, fentanyl, nifedipine, quinidine)
- Enzalutamide induces these enzymes and lowers their levels; many combinations are avoided.
What is monitored
- Blood pressure
- Neurological symptoms (seizure risk factors)
- Fall and fracture risk
- Cardiovascular symptoms
- PSA
Administration and safety
- Oral tablet or capsule once a day, at about the same time, with or without food; swallowed whole with water, not crushed, chewed or opened.
- Women who are or may be pregnant do not touch the capsules or tablets.
Nursing care
- Ask about any history of seizures, brain injury or drugs that lower the seizure threshold.
- Assess fall risk and teach home safety.
- Review all medicines for interactions: it lowers the levels of many drugs.
- Teach to report headache with confusion or vision changes, chest pain or facial swelling.
Pregnancy and breastfeeding
Only for men; it can harm a fetus, and men use condoms with a pregnant partner and effective contraception with a partner who could become pregnant, during treatment and for 3 months after.
Test yourself
Think of the answer, then tap the question to see it.
How does enzalutamide differ from bicalutamide at the receptor?
Both are competitive androgen receptor antagonists, but enzalutamide binds with several-fold higher affinity and is effective in castration-resistant disease.
Which neurological adverse effect requires screening for risk factors before enzalutamide?
Seizures; the drug crosses the blood-brain barrier.
Why can enzalutamide make warfarin or fentanyl less effective?
It induces CYP3A4, CYP2C9 and CYP2C19, speeding the metabolism of their substrates.
Related drugs
Related conditions
← Back to the class: Antiandrogens and androgen synthesis inhibitors
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Enzalutamide: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 73 (McGraw Hill, 2023).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.