Casodex 50 mg Tablets

Brand Name

The medication is marketed under the brand name Casodex, a widely recognized designation in the field of oncology and hormone-related therapies.

International Nonproprietary Name (INN)

The active substance within this product carries the international name bicalutamide, ensuring its consistent identification across global pharmacological standards.

Form of Release

Casodex is produced as film-coated tablets, intended for oral administration. These tablets are typically available in strengths of 50 mg or 150 mg, packaged in blister strips or bottles based on regional distribution practices.

Composition

Each tablet contains bicalutamide as the primary active ingredient, with dosages of either 50 mg or 150 mg depending on the prescribed treatment. The formulation includes several inactive components such as lactose monohydrate, which serves as a filler, and magnesium stearate, acting as a lubricant to aid in tablet production. Additional excipients like sodium starch glycolate facilitate disintegration, while the film coating consists of hypromellose, polyethylene glycol, and titanium dioxide, providing a smooth, protective layer and a white appearance. Trace amounts of other stabilizers may be present, tailored to maintain the drug’s integrity over time.

Pharmacologic Properties

Pharmacodynamics

Casodex exerts its therapeutic effect by functioning as a non-steroidal anti-androgen. It works by competitively binding to androgen receptors in target tissues, particularly in the prostate gland. This binding prevents androgens, such as testosterone and dihydrotestosterone (DHT), from activating these receptors, which are critical drivers of prostate cancer cell growth. By blocking this interaction, the medication inhibits the proliferation of malignant cells dependent on androgen signaling, slowing disease progression in conditions like advanced prostate cancer. Unlike steroidal anti-androgens, it does not suppress testosterone production directly, allowing for a distinct hormonal profile during treatment.

The blockade of androgen receptors also impacts the hypothalamic-pituitary axis, leading to a compensatory rise in luteinizing hormone (LH) and, consequently, testosterone levels in the blood. This phenomenon, while not negating the drug’s efficacy, distinguishes its mechanism from treatments that reduce androgen synthesis. Clinical evidence highlights its role in reducing prostate-specific antigen (PSA) levels, a key marker of prostate cancer activity, often within weeks of initiating therapy. Its selective action makes it a cornerstone in combination regimens, particularly alongside luteinizing hormone-releasing hormone (LHRH) analogs.

Pharmacokinetics

Upon oral ingestion, Casodex is well-absorbed from the gastrointestinal tract, with peak plasma concentrations typically achieved within 24 to 48 hours due to its slow absorption rate. Food intake has minimal influence on its bioavailability, offering flexibility in administration timing. The drug exhibits extensive plasma protein binding, exceeding 96%, which confines its distribution largely to the bloodstream and androgen-sensitive tissues.

Metabolism occurs predominantly in the liver, where cytochrome P450 enzymes, including CYP3A4, oxidize bicalutamide into inactive metabolites. This process is stereoselective, with the R-enantiomer—the pharmacologically active form—having a half-life of approximately 5 to 7 days, contributing to its once-daily dosing schedule. Excretion is balanced between urine and feces, with roughly equal proportions of metabolites eliminated through each route over several days. The prolonged half-life ensures sustained receptor blockade but also means detectable levels may linger for weeks after discontinuation.

Indications for Use

Casodex is prescribed primarily for the treatment of advanced prostate cancer in adult men. It is often used in combination with LHRH agonists, such as goserelin or leuprolide, to achieve maximal androgen blockade, addressing both testicular and adrenal androgen sources. This dual approach is particularly effective in managing metastatic disease, where controlling cancer spread is a priority.

In some regions, the 150 mg dose is indicated as monotherapy for locally advanced prostate cancer, offering an alternative to surgical castration or other systemic therapies. This use aims to delay progression and manage symptoms like urinary obstruction or bone pain without the need for additional hormonal suppression. The medication may also be employed in earlier-stage disease under specific protocols, though such applications often depend on physician discretion and local guidelines.

Contraindications

Casodex is not suitable for women or children, as its mechanism targets male-specific androgen pathways irrelevant to other populations. It is explicitly contraindicated in pregnancy due to potential risks of fetal harm, though this applies indirectly through precautions for male patients’ partners. Individuals with a known hypersensitivity to bicalutamide or any tablet component, such as lactose, should avoid its use, as allergic reactions could range from mild rashes to severe systemic responses.

Severe hepatic impairment poses another significant restriction, given the drug’s extensive liver metabolism. Patients with acute liver disease or a history of significant hepatotoxicity from similar agents must not receive this treatment, as it could exacerbate underlying conditions or lead to unpredictable drug accumulation.

Method of Administration and Dosage

Administration Guidelines

The tablets should be taken orally, swallowed whole with a glass of water to ensure proper delivery to the stomach. They can be consumed with or without food, providing ease of integration into daily routines. Breaking or crushing the tablets is not advised, as it may alter absorption and expose the patient to unnecessary irritation.

Dosage for Adults and Children

For adult men with advanced prostate cancer, the standard dose of Casodex is 50 mg once daily when combined with an LHRH analog. Treatment typically begins simultaneously with the agonist to mitigate the initial testosterone surge, known as the flare phenomenon. As monotherapy for locally advanced disease, a higher dose of 150 mg daily is recommended in some protocols. Consistency in timing enhances efficacy, though minor deviations are unlikely to disrupt outcomes. Children are not eligible for this therapy, as it is designed exclusively for adult male conditions.

Dose Adjustment in Specific Conditions

No dosage adjustments are generally required for renal impairment, as kidney function plays a limited role in clearing the drug. In mild to moderate liver dysfunction, the standard dose is usually tolerated, but caution is advised due to reliance on hepatic metabolism. Severe liver disease contraindicates use entirely, and no specific adjustments are outlined for less extreme cases, though monitoring liver function is prudent during therapy. Elderly patients typically follow the same regimen unless comorbidities suggest otherwise.

Side Effects

Casodex may induce a variety of side effects, though many patients experience only mild or manageable reactions. Common issues include hot flashes, reflecting the hormonal shift caused by androgen receptor blockade, and breast tenderness or gynecomastia, which can occur in over a third of users due to unopposed estrogen effects. Sexual dysfunction, such as reduced libido or erectile difficulties, is also frequent but varies in persistence.

Gastrointestinal disturbances like nausea or diarrhea may arise, typically resolving without intervention. Fatigue and weakness are reported occasionally, potentially linked to systemic hormonal changes. Liver function abnormalities, including elevated enzyme levels, occur in a small percentage of cases and warrant regular monitoring. Rare but serious reactions, such as interstitial lung disease or severe hepatotoxicity, have been documented, necessitating immediate medical attention if symptoms like shortness of breath or jaundice emerge.

Overdose

Symptoms of Overdose

Excessive intake of Casodex is unlikely to produce acute, life-threatening symptoms due to its pharmacological profile. Clinical studies with doses up to 600 mg daily showed no immediate severe toxicity, though prolonged overexposure might intensify common side effects like hot flashes, fatigue, or liver strain. Specific overdose symptoms remain poorly characterized, reflecting the drug’s gradual action.

First Aid Measures

In the event of an overdose, medical consultation is recommended, though urgent intervention is rarely needed. No antidote exists, so management focuses on supportive care, such as monitoring vital signs and liver function, and addressing any symptomatic complaints. Given the drug’s long half-life, effects may persist, but observation typically suffices unless complications develop.

Drug Interactions

Effects on Other Medications

Casodex can influence drugs metabolized by CYP3A4, as it weakly inhibits this enzyme. For instance, co-administration with warfarin may enhance anticoagulant effects, requiring closer monitoring of clotting parameters. Use with midazolam or similar agents could theoretically increase their sedative impact, though such interactions are rarely significant in practice. Combining it with LHRH analogs poses no pharmacokinetic conflicts, reinforcing their complementary roles in prostate cancer therapy.

Drugs that induce CYP3A4, like rifampicin, might accelerate bicalutamide clearance, potentially reducing efficacy, though evidence is limited. Patients should disclose all concurrent medications to their healthcare provider for a comprehensive interaction assessment.

Compatibility with Alcohol and Food

Alcohol consumption does not directly alter the drug’s performance, allowing patients to maintain moderate drinking habits if desired. Food intake similarly has negligible effects on absorption, so the medication can be taken alongside meals or on an empty stomach without compromising its action.

Special Precautions

Use During Pregnancy and Breastfeeding

Casodex is intended solely for men and is contraindicated in women, particularly during pregnancy. While not directly applicable to female patients, men taking the drug should ensure it is not handled by pregnant partners, as theoretical skin absorption risks remain unclear. Breastfeeding considerations do not apply, given its male-specific use, and no data exist on its presence in breast milk.

Men using this therapy do not face specific reproductive restrictions beyond general health considerations, as it does not affect sperm production directly. However, discussing family planning with a doctor is wise due to the underlying condition being treated.

Impact on Driving and Operating Machinery

The medication generally does not impair cognitive or motor skills, making it safe for most patients to drive or operate machinery. Fatigue or rare dizziness could affect some individuals, so assessing personal response during early use is advisable before engaging in such activities.

Considerations for Elderly and Pediatric Populations

Elderly men, a primary demographic for prostate cancer treatment, typically tolerate Casodex well, with no notable differences in efficacy or safety compared to younger adults. Age-related declines in liver function may heighten sensitivity in some cases, suggesting periodic evaluation. Pediatric use is not approved, as the drug’s purpose and effects are irrelevant to children, and safety in this group remains untested.