What it's for (Indications)
- Bicalutamide is indicated for the treatment of prostate cancer.
- Specifically, it is used in combination with a luteinizing hormone-releasing hormone (LHRH) analog or surgical castration for the management of advanced prostate cancer.
- This includes locally advanced, non-metastatic prostate cancer where the disease has spread outside the prostate gland but not to distant sites, and for metastatic prostate cancer where the disease has spread to other parts of the body.
- Its role is to block the effects of androgens, which stimulate prostate cancer growth.
- This combined approach is designed to achieve maximal androgen blockade, significantly improving outcomes for patients by reducing tumor burden, slowing disease progression, and alleviating symptoms associated with advanced prostate cancer.
- The decision to initiate bicalutamide therapy, particularly for locally advanced disease, should consider the potential benefits against the risks of long-term androgen deprivation.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | The recommended dosage of bicalutamide varies based on the specific indication for prostate cancer. For the treatment of locally advanced prostate cancer in combination with an LHRH analog or surgical castration, the usual dosage is 150 mg once daily. For metastatic prostate cancer, also in combination with an LHRH analog or surgical castration, the typical dosage is 50 mg once daily. Bicalutamide tablets are administered orally and can be taken with or without food. It is crucial to initiate bicalutamide therapy at the same time as the LHRH analog or surgical castration to ensure immediate maximal androgen blockade. The tablets should be swallowed whole and not crushed. Dosage adjustments for renal impairment are generally not necessary; however, caution should be exercised in patients with moderate to severe hepatic impairment, and liver function should be monitored closely. Adherence to the prescribed dosage and administration schedule is vital for treatment efficacy and patient safety. |
Safety & Warnings
Common Side Effects
- Bicalutamide treatment can lead to a range of side effects, which vary in severity and incidence.
- Commonly reported adverse reactions include hot flashes, pain (such as back pain, pelvic pain, or generalized pain), asthenia (weakness or lack of energy), constipation, nausea, diarrhea, and peripheral edema.
- Other frequent effects include nocturia, hematuria, anemia, and significant breast changes such as breast pain, tenderness, and gynecomastia (breast enlargement in men).
- More serious, though less common, adverse effects warrant close medical attention.
- These include hepatic dysfunction, which can range from asymptomatic transaminase elevations to severe, and in rare cases, fatal hepatic failure.
- Interstitial pneumonitis, presenting as dyspnea, cough, or fever, and cardiovascular events such as myocardial infarction or heart failure, have also been reported.
- Patients should be advised to report any new or worsening symptoms promptly to their healthcare provider for evaluation.
Serious Warnings
- Black Box Warning: Bicalutamide does not carry a formal FDA Black Box Warning. However, based on the significant and potentially life-threatening risks associated with its use, it is crucial for healthcare providers and patients to be fully aware of several serious warnings that demand close attention and monitoring during treatment. **Serious Hepatic Injury:** Cases of severe, and rarely fatal, hepatic failure have been reported. Liver function tests should be conducted regularly prior to and during treatment, and bicalutamide should be discontinued if liver enzyme elevations are significant (e.g., >2 times the upper limit of normal) or if jaundice or other symptoms of liver damage develop. **Cardiovascular Events:** An increased incidence of cardiovascular events, including myocardial infarction, heart failure, and stroke, has been noted in patients receiving bicalutamide, particularly when used in combination with an LHRH analog. Patients with a history of cardiovascular disease or risk factors should be carefully assessed and monitored throughout therapy. **Interstitial Pneumonitis:** While rare, interstitial pneumonitis has occurred, manifesting as dyspnea, cough, and fever, requiring prompt medical evaluation and treatment discontinuation if suspected. Patients should be thoroughly counseled on these serious potential risks and instructed to seek immediate medical attention if they experience any concerning symptoms.
- Several critical warnings are associated with bicalutamide therapy, necessitating careful patient monitoring.
- **Hepatic Impairment:** Severe and fatal hepatic failure has been reported in patients treated with bicalutamide.
- Liver function tests, including serum transaminases and bilirubin, should be performed prior to treatment initiation, at regular intervals during the first few months of therapy, and periodically thereafter, or immediately if symptoms suggestive of liver dysfunction (e.
- g.
- , jaundice, dark urine, abdominal pain) arise.
- If elevations of transaminases exceed twice the upper limit of normal, a thorough evaluation should be conducted, and bicalutamide may need to be discontinued.
- **Cardiovascular Events:** An increased risk of cardiovascular disorders, including myocardial infarction and heart failure, has been observed.
- Patients with pre-existing cardiovascular conditions should be carefully monitored.
- **Interstitial Pneumonitis:** Rare cases of interstitial pneumonitis, characterized by dyspnea, cough, and fever, have been reported; therapy should be discontinued if suspected.
- **Glucose Intolerance/Diabetes:** Androgen deprivation therapy may cause changes in glucose metabolism, potentially leading to or exacerbating diabetes; blood glucose should be monitored.
- **Angioedema and Anaphylaxis:** Hypersensitivity reactions, including angioedema and anaphylaxis, have occurred; treatment should be discontinued if severe reactions develop.
- Bicalutamide should not be used in women.
How it Works (Mechanism of Action)
Bicalutamide is a non-steroidal anti-androgen that exerts its therapeutic effects by specifically blocking the activity of androgens, which are hormones essential for the growth and survival of prostate cancer cells. In target tissues, bicalutamide and its primary active metabolite bind to androgen receptors, preventing the binding of endogenous androgens such as testosterone and dihydrotestosterone (DHT). This competitive inhibition at the receptor level effectively blocks the androgen-mediated signaling pathways that drive prostate cancer cell proliferation. By inhibiting androgen-stimulated cell growth and promoting apoptosis (programmed cell death) in prostate cancer cells, bicalutamide helps to shrink tumors, slow disease progression, and reduce symptoms. Its non-steroidal nature differentiates it from older anti-androgens, offering a more selective and generally better-tolerated pharmacological profile for long-term use in prostate cancer management.