Casodex (bicalutamide) is a nonsteroidal antiandrogen medication indicated for use in combination therapy with a luteinizing hormone-releasing hormone (LHRH) analog for the treatment of Stage D2 metastatic carcinoma of the prostate. It functions as a competitive antagonist at androgen receptors, effectively blocking the action of testosterone and dihydrotestosterone (DHT), which are primary drivers of prostate cancer growth and proliferation. This targeted mechanism offers a crucial component in the systemic management of advanced disease, providing a specific biochemical intervention to control tumor progression and manage symptoms associated with hormone-sensitive prostate cancer.

Features

• Active pharmaceutical ingredient: Bicalutamide
• Standard tablet strength: 50 mg
• Mechanism of action: Pure, nonsteroidal antiandrogen; competitive antagonist at cytosolic androgen receptors in target tissues
• Pharmacokinetic profile: Long elimination half-life (approximately 5.9 days), allowing for once-daily dosing
• Administration: Oral tablet
• Bioavailability: Well-absorbed; not significantly affected by food
• Metabolism: Extensively hepatic via oxidation and glucuronidation; stereospecific metabolism results in the R-enantiomer being the active form
• Excretion: Primarily via the kidneys and bile/feces

Benefits

• Provides effective androgen receptor blockade, directly inhibiting the stimulatory effects of androgens on prostate cancer cells.
• Used in combination with an LHRH analog, it helps mitigate the initial testosterone surge (“flare phenomenon”) that can cause temporary worsening of symptoms.
• Contributes to the reduction of tumor burden, slowing disease progression in metastatic settings.
• Can help manage cancer-related symptoms such as bone pain.
• Offers a convenient once-daily oral dosing regimen, supporting treatment adherence.
• Forms a cornerstone of combined androgen blockade (CAB), a established therapeutic strategy for advanced disease.

Common use

Casodex is primarily used as part of a combined androgen blockade (CAB) regimen for the treatment of metastatic (Stage D2) prostate cancer. It is co-administered with a luteinizing hormone-releasing hormone (LHRH) analog, such as leuprolide or goserelin. The LHRH analog suppresses testicular production of testosterone, achieving medical castration. Casodex complements this by blocking the action of any remaining androgens (from adrenal sources) and preventing the initial testosterone flare that can occur upon initiation of LHRH analog therapy. This combination provides a more complete androgen suppression. Its use is generally reserved for advanced, hormone-sensitive disease and is not indicated as a monotherapy or for early-stage prostate cancer.

Dosage and direction

The recommended adult dosage of Casodex for use in combination with an LHRH analog is one 50 mg tablet taken orally once a day, preferably at the same time each day. It is typically initiated concurrently with the LHRH analog therapy. The tablet can be taken with or without food. Treatment should be continued as long as the patient responds favorably and the clinical benefits outweigh potential risks. Dosage adjustment is not routinely required for elderly patients or those with mild to moderate renal impairment. Use in patients with severe hepatic impairment is not recommended. It is crucial that therapy is supervised by a physician experienced in the oncological management of prostate cancer.

Precautions

• Hepatotoxicity: Casodex use has been associated with rare instances of severe liver injury, including fulminant hepatitis, which can be fatal. Liver function tests (transaminases, bilirubin, alkaline phosphatase) must be measured prior to initiating treatment, at regular intervals for the first several months, and periodically thereafter.
• Photosensitivity: Reactions exhibiting photosensitivity have been reported. Patients should be advised to take protective measures against UV exposure, such as using sunscreen and wearing protective clothing.
• Glucose Control: Androgen deprivation therapy can impact glucose metabolism. Blood glucose levels should be monitored periodically, particularly in patients with diabetes.
• Lipids: Androgen deprivation can alter lipid profiles (e.g., increased serum triglycerides and cholesterol). Lipid levels should be monitored periodically.
• Vitamin K-dependent Clotting Factors: Decreases in prothrombin time have been observed. Caution is advised when administering Casodex concurrently with anticoagulants like warfarin; close monitoring of prothrombin time (INR) is recommended.
• Pulmonary Disorders: Interstitial lung disease, including pulmonary fibrosis, has been reported rarely. Patients presenting with new or worsening respiratory symptoms should be promptly evaluated.

Contraindications

Casodex is contraindicated in patients with known hypersensitivity to bicalutamide or any component of the formulation. It must not be administered to female patients and is absolutely contraindicated in pregnancy due to the potential for causing fetal harm by disrupting normal sexual development. Its use is also contraindicated in patients with severe hepatic impairment.

Possible side effect

Adverse reactions are often related to the intended pharmacological effect of androgen deprivation. Common side effects may include:

• Very Common (≥10%): Hot flashes (flushes), breast tenderness (gynecomastia), breast enlargement, nausea, constipation, asthenia, pain, back pain, pelvic pain.
• Common (1% to 10%): Diarrhea, vomiting, dyspepsia, dry mouth, dizziness, insomnia, depression, decreased libido, impotence, sweating, rash, alopecia, peripheral edema, weight gain, hypertension.
• Uncommon (0.1% to 1%): Hepatic changes (elevated transaminases, jaundice), pruritus, dry skin, hirsutism, heart failure, angina pectoris.
• Rare (<0.1%): Serious hepatotoxicity (including hepatic failure), photosensitivity reactions, interstitial lung disease, anaphylactic reactions.

Drug interaction

• Anticoagulants (e.g., Warfarin): Casodex can inhibit the metabolism of warfarin, potentially increasing its anticoagulant effect and the risk of bleeding. Frequent monitoring of prothrombin time (INR) is essential, and warfarin dosage may require adjustment.
• CYP3A4 Substrates: Bicalutamide is a weak inhibitor of CYP3A4. Caution is advised when co-administering with drugs that are primarily metabolized by CYP3A4 and have a narrow therapeutic index (e.g., cyclosporine, some calcium channel blockers, quinidine).
• Other Medications Metabolized by CYP: Due to its own metabolism by CYP3A4, inducers or inhibitors of this enzyme could potentially alter bicalutamide plasma concentrations, though the clinical significance is likely limited.

Missed dose

If a dose of Casodex is missed, the patient should take it as soon as remembered on that same day. If the missed dose is not remembered until the next day, the patient should skip the missed dose and take only the regularly scheduled dose. Patients should not take a double dose to make up for a missed one. Maintaining a consistent daily schedule is important for optimal therapeutic effect.

Overdose

There is no specific antidote for Casodex overdose. Expected consequences would be an extension of its known pharmacological effects, particularly related to androgen blockade. Treatment should be symptomatic and supportive. Since bicalutamide is highly protein-bound, dialysis is not likely to be an effective means of enhancing elimination. In the event of a suspected overdose, medical attention should be sought immediately.

Storage

Store Casodex tablets at room temperature, between 20°C to 25°C (68°F to 77°F). Excursions are permitted between 15°C and 30°C (59°F and 86°F). The tablets should be kept in their original blister packaging or bottle to protect them from light and moisture. Keep all medications out of the reach of children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard any expired or no longer needed medication through a medicine take-back program.

Disclaimer

This information is intended for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here. The content provided is based on the manufacturer’s prescribing information but may not be exhaustive.

Reviews

• Oncologist’s Perspective (Clinical Efficacy): “In my practice, Casodex remains a standard component of combined androgen blockade for metastatic prostate cancer. Its once-daily dosing is convenient for patients, and its role in preventing the LHRH agonist flare is well-established. We vigilantly monitor liver function tests as per guidelines, but the efficacy profile in appropriate patient populations is solid.”
• Urologist’s Perspective (Patient Management): “The tolerability profile is generally acceptable for most men, with hot flashes and gynecomastia being the most frequent complaints we manage. The key is setting patient expectations beforehand. The drug’s role in the therapeutic arsenal is clearly defined for advanced disease.”
• Pharmacist’s Perspective (Safety Monitoring): “Our primary role is counseling on adherence and reinforcing the critical importance of regular liver function monitoring. We also emphasize the potential for drug interactions, particularly with warfarin, ensuring patients understand the need for increased INR checks if they are on both medications.”
• Patient Experience (Tolerability): “The hot flashes were significant but manageable. Knowing it was part of a treatment plan to fight the cancer made it easier to accept the side effects. The once-a-day pill was straightforward to remember.”