Bicalutamide (Casodex): Anti-androgen for Prostate Cancer
Bicalutamide is a widely used anti-androgen therapy for the treatment of prostate cancer. Prostate tumors are fueled by male hormones (androgens like testosterone). Bicalutamide acts as a shield: it competitively binds to androgen receptors on the cancer cells, preventing testosterone from attaching and stimulating tumor growth.
Commonly known by the brand name Casodex, it is a non-steroidal anti-androgen. Unlike surgical or chemical castration alone, it does not stop hormone production but stops the hormones from working at the cellular level.
It is predominantly used in combination with LHRH analogues (chemical castration) to achieve "Complete Androgen Blockade," neutralizing even the small amounts of androgens produced by the adrenal glands.
Indications
- Advanced Prostate Cancer: Used in combination therapy with an LHRH analogue or surgical castration for the treatment of stage D2 metastatic carcinoma of the prostate.
- Flare Prevention: Prescribed briefly before starting LHRH agonists to prevent the initial testosterone surge (tumor flare) that can cause bone pain or spinal cord compression.
- Locally Advanced Disease: Sometimes used as monotherapy (high dose 150 mg) in select cases where immediate castration is not indicated.
Dosage and administration
Adherence to the daily schedule is crucial for suppressing the tumor.
- Standard Dose (Combination Therapy): 50 mg (one tablet) taken once daily. Usually started at the same time as, or shortly before, the LHRH analogue.
- High Dose (Monotherapy): 150 mg taken once daily (only for specific indications prescribed by an oncologist).
- Instructions: Swallow the tablet whole with water. It can be taken with or without food. Try to take it at the same time every day.
- Gender and Age: Contraindicated in women and children.
- Liver Disease: Severe hepatic impairment (caution is advised as the drug is extensively metabolized in the liver).
- Concomitant use with terfenadine, astemizole, or cisapride.
- Hypersensitivity to bicalutamide.
Side effects are primarily due to the pharmacological action of androgen deprivation.
- Very Common: Hot flushes, breast tenderness or swelling (gynecomastia), decreased libido, erectile dysfunction.
- Gastrointestinal: Nausea, diarrhea, constipation.
- Liver: Hepatotoxicity (elevated liver enzymes). Regular liver function tests are required during treatment.
- General: Asthenia (weakness), fatigue, dizziness.
