Bicalutamide is a non-steroidal antiandrogen medication primarily used in the treatment of prostate cancer. It works by blocking the action of androgens (male hormones such as testosterone), which can stimulate the growth of prostate cancer cells. By preventing these hormones from binding to androgen receptors, bicalutamide helps slow or stop the progression of hormone-dependent tumors. The drug is commonly prescribed in combination with other hormone therapies, such as luteinizing hormone-releasing hormone (LHRH) analogues, or used alone in certain clinical situations. Bicalutamide is taken orally and is generally well tolerated, though it can cause side effects related to hormonal changes.
BRAND NAMES
Casodex – the most widely known brand
Bicalutamid Sandoz – generic versions in some regions
Bicalutamide Teva – other generic formulations
MECHANISM OF ACTION
Bicalutamide is a nonsteroidal anti-androgen that blocks androgen receptors in prostate cells, preventing testosterone and DHT from stimulating cancer growth. It does not lower hormone levels but stops their effect at the receptor, slowing tumor progression.
PHARMACOKINETICS
Absorption
Bicalutamide is well absorbed orally, with peak blood levels usually reached around 1–2 hours after a dose. Food does not significantly affect its absorption, and it has high bioavailability, allowing effective systemic exposure from tablets.
Distribution
Bicalutamide is highly protein-bound, with about 96–99% bound to plasma proteins, mainly albumin. It is widely distributed throughout the body, including prostate tissue, which contributes to its effectiveness in treating prostate cancer.
Metabolism
Bicalutamide is primarily metabolized in the liver through cytochrome P450 enzymes, mainlyCYP3A4. It undergoes oxidation and glucuronidation to form inactive metabolites, which are then eliminated from the body.
Excretion
Bicalutamide and its metabolites are mainly excreted in the urine (about 60%) and partly in the feces (about 40%). Most of the drug is eliminated as inactive metabolites, with a half-life of approximately 6–7 days in adults.
PHARMACODYNAMICS
Bicalutamide is a nonsteroidal anti-androgen that blocks androgen receptors, preventing testosterone and DHT from stimulating prostate cancer growth. It does not reduce hormone levels but inhibits their effects at the receptor, slowing tumor progression.
ADMINISTRATION
Bicalutamide is administered orally in tablet form, usually once daily. It is commonly taken with or without food at the same time each day to maintain consistent blood levels.
DOSAGE AND STRENGTH
Bicalutamide is commonly available in 50 mg and 150 mg tablets.
50 mg/day – often used in combination with other hormone therapies for advanced prostate cancer.
150 mg/day – sometimes used as monotherapy for non-metastatic prostate cancer.
FOOD INTERACTIONS
Bicalutamide can be taken with or without food, as food does not significantly affect its absorption. There are no major dietary restrictions, but patients should maintain a consistent routine and follow their doctor’s instructions for best results.
DRUG INTERACTIONS
Warfarin – may increase anticoagulant effects, requiring closer INR monitoring.
CYP3A4 inducers (e.g., rifampin, carbamazepine) – can reduce bicalutamide levels, lowering effectiveness.
CYP3A4 inhibitors (e.g., ketoconazole, itraconazole) – can increase bicalutamide levels, raising the risk of side effects.
Other anti-androgens or hormone therapies – may have additive effects on hormone pathways.
CONTRAINDICATIONS
Hypersensitivity to bicalutamide or any of its ingredients.
Severe liver impairment or active liver disease, as the drug is metabolized in the liver.
Pregnancy and breastfeeding – not applicable for women taking the drug, as it can cause fetal harm.
SIDE EFFECTS
Hot flashes
Breast tenderness or enlargement (gynecomastia)
Nausea
Diarrhea
Fatigue
TOXICITY
Bicalutamide toxicity mainly affects the liver, potentially causing elevated enzymes or hepatitis, and can rarely impact the heart. Overdose may lead to nausea, vomiting, diarrhea, or fatigue, with management focused on monitoring and supportive care.
