Pharmacology of bicalutamide

Bicalutamide is a nonsteroidal antiandrogen (NSAA) used primarily in the treatment of prostate cancer. It is a pure androgen receptor (AR) antagonist that prevents androgens like testosterone and dihydrotestosterone (DHT) from stimulating the AR.

Pharmacodynamics

Bicalutamide acts as a pure antagonist of the androgen receptor (AR). Unlike earlier antiandrogens such as flutamide and nilutamide, bicalutamide does not induce DNA damage, and is thus classified as a "pure" antiandrogen. It competes with testosterone and its powerful metabolite, dihydrotestosterone (DHT) for binding to ARs in tissues like the prostate gland. By doing so, it prevents them from stimulating the AR.

Pharmacokinetics

Bicalutamide is well-absorbed when taken by mouth and can be taken with or without food. It is highly protein-bound and has a very long elimination half-life, allowing for once-daily dosing. Bicalutamide is extensively metabolized in the liver via hydroxylation and glucuronidation. Its metabolites are eliminated in both urine and feces.

Clinical use

Bicalutamide is used in the treatment of prostate cancer in men. It is also used as an adjunct to surgical castration in the treatment of advanced prostate cancer. In addition, it has been used off-label for the treatment of other androgen-dependent conditions, including hirsutism, acne, and androgenic alopecia.

Side effects

The most common side effects of bicalutamide are hot flashes, breast tenderness and enlargement, and sexual dysfunction. Less common side effects include gastrointestinal disturbances, liver function test abnormalities, and an increased risk of heart failure.

See also

• Antiandrogen
• Prostate cancer
• Androgen receptor
• Testosterone
• Dihydrotestosterone

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