Brand name: Casodex [Web]
Drug class: Antineoplastic Agents

Medically reviewed by Drugs.com on Jul 25, 2023. Written by ASHP.

Introduction

Antineoplastic agent; a nonsteroidal antiandrogen.

Uses for Bicalutamide

Prostate Cancer

Bicalutamide 50 mg once daily used in combination with a luteinizing hormone-releasing hormone (LHRH) analog (e.g., goserelin or leuprolide acetate) for the treatment of metastatic (stage D2) prostate cancer.

Guidelines state that clinicians should not offer first-generation antiandrogens, including bicalutamide, in combination with LHRH agonists in patients with metastatic hormone-sensitive prostate cancer, except to block testosterone flare.

Bicalutamide 150 mg daily should not be used alone or in combination with other treatments; dosage regimen associated with potentially increased risk of mortality compared to castration in studies enrolling patients with locally advanced (T3–4, NX, M0) or metastatic (M1) prostate cancer^{† [off-label]} .

Bicalutamide Dosage and Administration

General

Pretreatment Screening

• Measure serum transaminase levels prior to treatment with bicalutamide.

Patient Monitoring

• Monitor serum transaminase levels at regular intervals during the first 4 months of treatment, and periodically thereafter. If signs or symptoms of liver dysfunction occur (e.g., nausea, vomiting, abdominal pain, fatigue, anorexia, “flu-like” symptoms, dark urine, jaundice, or right upper quadrant tenderness), assess serum transaminase levels. If jaundice occurs or alanine aminotransferase (ALT) increases above 2 times the upper limit of normal (ULN), discontinue bicalutamide and closely monitor liver function.

• Consider monitoring prostate specific antigen (PSA) concentrations periodically to assess response to therapy; if PSA levels rise while on bicalutamide, evaluate for clinical disease progression.

• Closely monitor the prothrombin time (PT) and international normalized ratio (INR) in patients on concomitant warfarin therapy, and adjust the anticoagulant dosage as necessary.

• Consider monitoring blood glucose in patients treated with bicalutamide in combination with LHRH agonists.

Other General Considerations

• Initiate bicalutamide and LHRH analog therapy concomitantly.

Administration

Oral Administration

Administer orally once daily at the same time each day (morning or evening) without regard to meals.

If a dose of bicalutamide is missed, take the prescribed dose at the next scheduled time; do not administer an additional dose to replace the missed dose.

Dosage

Adults

Prostate Cancer

Oral

50 mg once daily in combination with a LHRH analog. Treatment with bicalutamide and the LHRH analog should be initiated concomitantly.

Special Populations

Hepatic Impairment

No dosage adjustment necessary.

Renal Impairment

No dosage adjustment necessary.

Geriatric Use

No specific dosage recommendations at this time.

Cautions for Bicalutamide

Contraindications

• Pregnancy.

• Not indicated for use in females.

• History of hypersensitivity to bicalutamide or any component of the preparation. Hypersensitivity reactions such as angioneurotic edema and urticaria have occurred.

Warnings/Precautions

Hepatitis

Severe liver injury reported, sometimes resulting in hospitalization and/or death; manifestations generally occurred within first 3–4 months of therapy.

Possible hepatitis or marked increases in serum concentrations of hepatic transaminases.

Measure serum transaminase concentrations prior to initiation of therapy, at regular intervals during the first 4 months, and periodically thereafter.

Immediately measure serum transaminase (especially ALT) concentrations if manifestations suggestive of liver dysfunction occur.

Immediately discontinue if jaundice develops or serum ALT concentration is >2 x ULN; monitor liver function closely thereafter.

Hemorrhage with Concomitant Use of Coumarin Anticoagulant

Excessive prolongation of PT and INR have been reported post-marketing in patients on concomitant warfarin therapy. Closely monitor PT and INR and adjust dosage of warfarin as necessary during bicalutamide treatment.

Gynecomastia and Bone Pain

Gynecomastia and bone pain reported in 38 and 39% of patients, respectively, receiving bicalutamide 150 mg as monotherapy for prostate cancer.

Glucose Tolerance

Reduction in glucose tolerance, presenting as diabetes or loss of glycemic control, has occurred in patients receiving LHRH agonists. Consider monitoring blood glucose in patients on bicalutamide and LHRH combination therapy.

Laboratory Tests

Consider regularly monitoring serum PSA to assess response; if PSA increases, evaluate for possible disease progression.

Specific Populations

Pregnancy

May cause fetal harm; contraindicated in pregnant females.

Lactation

Contraindicated in females.

Females and Males of Reproductive Potential

Advise male patients with female partners of reproductive potential to use effective contraception during treatment and for 130 days after stopping bicalutamide. Can inhibit spermatogenesis and impair fertility in males of reproductive potential; long-term effects on male fertility not evaluated.

Pediatric Use

Safety and efficacy not established.

Geriatric Use

No significant relationship between age and steady-state levels of bicalutamide or active R-enantiomer.

Hepatic Impairment

Use with caution in patients with moderate to severe hepatic impairment. Consider periodic liver function tests in patients with hepatic impairment receiving long-term therapy.

Renal Impairment

No significant impact on elimination of bicalutamide or active R-enantiomer.

Common Adverse Effects

Adverse effects (≥10%, receiving bicalutamide plus a LHRH analog): Hot flashes, pain (including general, back, pelvic, and abdominal), asthenia, constipation, infection, nausea, peripheral edema, dyspnea, diarrhea, hematuria, nocturia, anemia.

Drug Interactions

Does not induce CYP isoenzymes. In vitro, R-enantiomer of bicalutamide has been shown to inhibit CYP3A4 and to have lesser inhibitory effects on CYP2C9, CYP2C19, and CYP2D6.

Drugs Metabolized by Hepatic Microsomal Enzymes

CYP3A4 Substrates

Use caution with coadministration of CYP3A4 substrates.

Protein-bound Drugs

Bicalutamide is highly protein bound (96%); may displace certain medications from protein binding sites.

Specific Drugs

Bicalutamide Pharmacokinetics

Absorption

Bioavailability

Well-absorbed following oral administration; absolute bioavailability is unknown.

Food

Food has no clinically important effect on rate or extent of absorption.

Distribution

Plasma Protein Binding

96%.

Elimination

Metabolism

Undergoes stereospecific metabolism in the liver.

Active R-enantiomer is predominantly oxidized to an inactive metabolite followed by glucuronidation. Inactive S-enantiomer is principally metabolized by glucuronidation.

S-enantiomer is rapidly cleared relative to the R-enantiomer; R-enantiomer accounts for about 99% of total steady-state plasma concentrations.

Elimination Route

Both parent and metabolite glucuronides are eliminated in urine and feces.

Half-life

Approximately 5.8 days (R-enantiomer).

Special Populations

Half-life of R-enantiomer was increased approximately 76% in patients with severe hepatic impairment.

Stability

Storage

Oral

Tablets

20–25°C.

Actions

• A selective antiandrogen with no androgenic or progestational activity in various animal models.

• Competitively blocks nuclear androgen receptors in target tissues (e.g., adrenal cortex, prostate, seminal vesicles).

• Blockade of androgen receptors in the hormone-sensitive tumor cells may result in growth arrest or transient tumor regression through inhibition of androgen-dependent DNA and protein synthesis.

• Inhibits initial androgenic stimulation and potential exacerbation of symptoms (e.g., bone pain, urinary obstruction, liver pain, impending spinal cord compression) associated with the first month of LHRH analog therapy.

Advice to Patients

• Risk of potential liver toxicity. Importance of notifying clinicians if nausea, vomiting, abdominal pain, or jaundice occurs.

• Importance of initiating bicalutamide concomitantly with luteinizing hormone-releasing hormone (LHRH) analog and of not interrupting or discontinuing therapy without consulting a clinician.

• Advise male patients with female partners of reproductive potential to use effective contraception during treatment with bicalutamide and for 130 days after the final dose.

• Importance of closely monitoring the prothrombin time (PT) and international normalized ratio (INR) in patients on concomitant warfarin therapy. Advise patients to notify their clinician of any bleeding or spontaneous bruising while on bicalutamide and anticoagulants.

• Inform patients that diabetes or loss of glycemic control can occur with use of a luteinizing hormone-releasing hormone (LHRH) analog. Consider advising patients to monitor blood glucose levels.

• Inform patients of risk of photosensitivity with bicalutamide therapy. Patients should avoid excessive direct exposure to sunlight or ultraviolet light and wear sunscreen.

• Advise patients that bicalutamide may increase somnolence; patients who experience somnolence should exercise caution when driving or operating machinery.

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as concomitant illnesses.

• Importance of informing patients of other important precautionary information.

Additional Information

The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer’s labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

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