Bicalutamide tablets for metastatic prostate cancer treatment

Bicalutamide tablets are an oral antiandrogen medication used in combination with luteinizing hormone-releasing hormone (LHRH) analogs for the treatment of Stage D2 metastatic prostate cancer. The tablets contain 50 mg of bicalutamide and work by inhibiting androgen receptors, thereby blocking the effects of male hormones that promote prostate cancer growth.

Approved use: Bicalutamide 50 mg tablets are indicated for use in combination with an LHRH analog to treat men with Stage D2 metastatic carcinoma of the prostate.

Population: Adult males with advanced prostate cancer requiring androgen deprivation therapy.

Bicalutamide

Bicalutamide acts as an androgen receptor inhibitor, blocking the action of male hormones (androgens) such as testosterone on prostate cancer cells. This inhibition helps reduce cancer growth since prostate tumors rely on androgens for stimulation.

Adults: Take one 50 mg tablet once daily, at the same time each day (morning or evening), with or without food.

Bicalutamide treatment should start simultaneously with an LHRH analog.

Missed Dose: If a dose is missed, take the next dose at the scheduled time. Do not take a double dose.

Renal Impairment: No dosage adjustment needed for renal impairment.

Hepatic Impairment: No adjustment is necessary for mild to moderate liver impairment. Although the half-life increases in severe hepatic impairment, dosage adjustment is not required.

• Known hypersensitivity to bicalutamide or any tablet components (including reactions such as angioneurotic edema or urticaria).
• Use in women (no approved indication).
• Pregnancy due to potential for fetal harm.

• Hepatotoxicity: Severe liver injury and fatal hepatic failure have occurred. Monitor liver enzymes before treatment, regularly during the first four months, and periodically thereafter. Discontinue bicalutamide immediately if ALT rises above twice the upper limit of normal or if jaundice develops.
• Bleeding Risk: Bicalutamide may increase prothrombin time (PT) and International Normalized Ratio (INR) in patients on coumarin anticoagulants, leading to serious bleeding. Close PT/INR monitoring and anticoagulant dose adjustments are necessary.
• Gynecomastia and Breast Pain: Reported especially with the 150 mg dose; breast enlargement and pain should be noted.
• Glucose Tolerance: LHRH analogs can reduce glucose tolerance; monitor blood glucose, particularly in diabetics receiving combination therapy.
• PSA Monitoring: Regular monitoring of prostate-specific antigen (PSA) is advised to evaluate treatment response and detect disease progression.

Common adverse reactions (>10%) when combined with LHRH analog: hot flashes (53%), pain (general, back, pelvic, abdominal), asthenia, constipation, infection, nausea, peripheral edema, dyspnea, diarrhea, hematuria, nocturia, and anemia.

Other frequent side effects (≥5%) include: hypertension, increased liver enzymes, dyspepsia, flatulence, anorexia, vomiting, anemia, weight changes, bone pain, myasthenia, arthritis, dizziness, paresthesia, insomnia, anxiety, depression, cough, pharyngitis, bronchitis, rash, sweating, gynecomastia, impotence, breast pain, urinary symptoms.

Post-marketing reports: Interstitial lung disease (including pneumonitis and fibrosis, some fatal), photosensitivity, and serious hemorrhage in patients on coumarin anticoagulants.

• Bicalutamide inhibits CYP3A4 and, to a lesser extent, CYP2C9, 2C19, and 2D6 enzymes; co-administration with CYP3A4 substrates (e.g., midazolam) may increase their levels.
• Bicalutamide can displace coumarin anticoagulants from protein binding sites, increasing bleeding risk; monitor PT/INR closely and adjust anticoagulant dose as needed.
• No clinically significant interactions with LHRH analogs have been observed.

Pregnancy: Bicalutamide is contraindicated in pregnant women as it can cause fetal harm, primarily abnormal development of male reproductive organs, demonstrated in animal studies. No human data are available.

Lactation: There is no information on presence of bicalutamide in human milk or effects on breastfed infants. Bicalutamide has been detected in rat milk.