What Is Bicalutamide (Casodex)?


Casodex (bicalutamide) is an androgen receptor inhibitor, also called an antiandrogen or a nonsteroidal antiandrogen (NSAA), used in combination with other hormone therapies called an LHRH agonists (also called GnRH agonists). It is indicated for use in individuals with metastatic prostate cancer (prostate cancer that has spread to the rest of the body). Casodex is an orally administered medication that comes in tablet form. Individuals taking Casodex should also be monitored for changes in liver functioning as well as for any changes in blood glucose or prostate-specific antigen (PSA).

What are the ingredients in Casodex?

The active ingredient in Casodex is bicalutamide, the nonsteroidal antiandrogen.

How does Casodex work?

Casodex’s active ingredient binds to the androgen receptors in the body. Casodex blocks testosterone and other androgens from activating these receptors. Prostate cancer tumors are often fueled to grow by androgens, including testosterone. Turning off the body’s ability to respond to testosterone can potentially halt tumor growth. In addition, Casodex can be used during early stages of other hormone therapies, such as treatment with Gonadotropin-Releasing Hormone (GnRH) agonists, in order to block the initial surge of testosterone, called tumor flare, that can come along with these medications. The surge of testosterone at the beginning of some of these treatment methods can contribute to rapid tumor growth before it is halted, potentially leading to life-threatening issues such as spinal cord compression.

What are the possible side effects of Casodex?

Multiple clinical trials evaluated the safety and efficacy of Casodex. The most common side effects of Casodex include hot flashes, swelling or pain of the breasts, pain in general, fatigue, infection, nausea, constipation, swelling of the limbs, diarrhea, anemia, increased urinary frequency, especially at night, and blood in the urine. This is not an exhaustive list of all potential side effects of Casodex. Talk to your healthcare provider or pharmacist for further information.

Things to note about Casodex

Several rare but more serious side effects can accompany Casodex including problems with your liver. Individuals should be closely monitored for signs of these serious side effects, and blood tests to assess liver function should be performed regularly. Alert your provider immediately if you notice any of the following symptoms:

  • Nausea and vomiting
  • Stomach or abdominal pain
  • Flu-like symptoms like soreness or muscle aches
  • Fatigue
  • Brown urine
  • Yellowing of the skin or whites of eyes (jaundice)
  • Loss of appetite
  • Inability to urinate
  • Difficulty breathing

Additionally, using Casodex with LHRH (or GnRH) agonist may affect blood glucose levels. Individuals taking Casodex should have their blood glucose continuously monitored. Also, treatment with Casodex without an LHRH agonist may lead to breast pain and swelling in men.

Before staring Casodex talk to your provider if you:

  • Have any liver problems
  • Are taking any blood thinners
  • Have diabetes or poor sugar control
  • Have a partner who is pregnant or could become pregnant
  • Have any other medical conditions
  • Are currently taking any other medications, vitamins, or herbal supplements

You should also contact your provider if you notice any signs of an allergic reaction to the medication, including chest pain or difficulty breathing. Skin sensitivity has been reported with Casodex, so it is important to use sunscreen and avoid sunlamps, tanning beds, and excessive sunlight if possible. It is also important to consult the prescribing information for any other medications taken with Casodex, including LHRH agonists.

Dosing information

Casodex is administered orally and is commonly taken with a LHRH (or GnRH) agonist. Typically, Casodex is taken once daily, and comes in a 50 mg tablet. Your provider will determine the appropriate dosage and administration schedule for you, as well as the appropriate dosage and administration of any other medications taken with Casodex. It is important to follow this schedule exactly as instructed, and not to stop taking Casodex or any accompanying medications on your own. If you miss a dose of Casodex, take your next dose at the regularly scheduled time, and do not try to make up for missed dosages. Casodex can be taken with or without food. If you take too much Casodex, seek emergency medical attention immediately.1

Written by: Casey Hribar | Last reviewed: October 2017
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