Flutamide

Flutamide
Black Box Warning
Adult Indications & Dosage
Pediatric Indications & Dosage
Contraindications
Warnings & Precautions
Adverse Reactions
Drug Interactions
Use in Specific Populations
Administration & Monitoring
Overdosage
Pharmacology
Clinical Studies
How Supplied
Images
Patient Counseling Information
Precautions with Alcohol
Brand Names
Look-Alike Names

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Deepika Beereddy, MBBS [2]

Disclaimer

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Black Box Warning

WARNINGS See full prescribing information for complete Boxed Warning. Hepatic Injury: There have been postmarketing reports of hospitalization and rarely death due to liver failure in patients taking flutamide. Evidence of hepatic injury included elevated serum transaminase levels, jaundice, hepatic encephalopathy and death related to acute hepatic failure. The hepatic injury was reversible after discontinuation of therapy in some patients. Approximately half of the reported cases occurred within the initial 3 months of treatment with flutamide. Serum transaminase levels should be measured prior to starting treatment with flutamide. Flutamide is not recommended in patients whose ALT values exceed twice the upper limit of normal. Serum transaminase levels should then be measured monthly for the first 4 months of therapy, and periodically thereafter. Liver function tests also should be obtained at the first signs and symptoms suggestive of liver dysfunction, e.g., nausea, vomiting, abdominal pain, fatigue, anorexia, “flu-like” symptoms, hyperbilirubinuria, jaundice or right upper quadrant tenderness. If at any time, a patient has jaundice, or their ALT rises above 2 times the upper limit of normal, flutamide should be immediately discontinued with close follow-up of liver function tests until resolution.

Overview

Flutamide is an androgen antagonist that is FDA approved for the treatment of carcinoma of prostate, stage B2, C or D2, in combination with an LHRH agonist. There is a Black Box Warning for this drug as shown here. Common adverse reactions include rash, hot sweats, diarrhea, nausea.

Adult Indications and Dosage

FDA-Labeled Indications and Dosage (Adult)

Carcinoma of prostate, Stage B2, C or D2, in combination with an LHRH agonist

• Flutamide capsules are indicated for use in combination with LHRH agonists for the management of locally confined Stage B2-C and Stage D2 metastatic carcinoma of the prostate.

Stage B2-C Prostatic Carcinoma

Treatment with flutamide capsules and the goserelin acetate implant should start 8 weeks prior to initiating radiation therapy and continue during radiation therapy.

Stage D2 Metastatic Carcinoma

To achieve benefit from treatment, flutamide capsules should be initiated with the LHRH agonist and continued until progression.

• Dosing Information

• 250 mg ORALLY every 8 hr in conjunction with a luteinizing hormone-releasing hormone (LHRH) agonist; begin 8 weeks prior to initiating radiation therapy and continue during radiation therapy.

Off-Label Use and Dosage (Adult)

Guideline-Supported Use

• There is limited information regarding Off-Label Guideline-Supported Use of Flutamide in adult patients.

Non–Guideline-Supported Use

• There is limited information regarding Off-Label Non–Guideline-Supported Use of Flutamide in adult patients.

Pediatric Indications and Dosage

FDA-Labeled Indications and Dosage (Pediatric)

• There is limited information regarding FDA-Labeled Use of Flutamide in pediatric patients.

Off-Label Use and Dosage (Pediatric)

Guideline-Supported Use

• There is limited information regarding Off-Label Guideline-Supported Use of Flutamide in pediatric patients.

Non–Guideline-Supported Use

• There is limited information regarding Off-Label Non–Guideline-Supported Use of Flutamide in pediatric patients.

Contraindications

• Condition1

Warnings

WARNINGS See full prescribing information for complete Boxed Warning. Hepatic Injury: There have been postmarketing reports of hospitalization and rarely death due to liver failure in patients taking flutamide. Evidence of hepatic injury included elevated serum transaminase levels, jaundice, hepatic encephalopathy and death related to acute hepatic failure. The hepatic injury was reversible after discontinuation of therapy in some patients. Approximately half of the reported cases occurred within the initial 3 months of treatment with flutamide. Serum transaminase levels should be measured prior to starting treatment with flutamide. Flutamide is not recommended in patients whose ALT values exceed twice the upper limit of normal. Serum transaminase levels should then be measured monthly for the first 4 months of therapy, and periodically thereafter. Liver function tests also should be obtained at the first signs and symptoms suggestive of liver dysfunction, e.g., nausea, vomiting, abdominal pain, fatigue, anorexia, “flu-like” symptoms, hyperbilirubinuria, jaundice or right upper quadrant tenderness. If at any time, a patient has jaundice, or their ALT rises above 2 times the upper limit of normal, flutamide should be immediately discontinued with close follow-up of liver function tests until resolution.

• Description

Precautions

• Description

Adverse Reactions

Clinical Trials Experience

There is limited information regarding Clinical Trial Experience of Flutamide in the drug label.

Body as a Whole

Cardiovascular

Digestive

Endocrine

Hematologic and Lymphatic

Metabolic and Nutritional

Musculoskeletal

Neurologic

Respiratory

Skin and Hypersensitivy Reactions

Special Senses

Urogenital

Miscellaneous

Postmarketing Experience

There is limited information regarding Postmarketing Experience of Flutamide in the drug label.

Body as a Whole

Cardiovascular

Digestive

Endocrine

Hematologic and Lymphatic

Metabolic and Nutritional

Musculoskeletal

Neurologic

Respiratory

Skin and Hypersensitivy Reactions

Special Senses

Urogenital

Miscellaneous

Drug Interactions

• Drug

• Description

Use in Specific Populations

Pregnancy

Pregnancy Category (FDA):

• Pregnancy Category

Pregnancy Category (AUS):

• Australian Drug Evaluation Committee (ADEC) Pregnancy Category

There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Flutamide in women who are pregnant.

Labor and Delivery

There is no FDA guidance on use of Flutamide during labor and delivery.

Nursing Mothers

There is no FDA guidance on the use of Flutamide with respect to nursing mothers.

Pediatric Use

There is no FDA guidance on the use of Flutamide with respect to pediatric patients.

Geriatic Use

There is no FDA guidance on the use of Flutamide with respect to geriatric patients.

Gender

There is no FDA guidance on the use of Flutamide with respect to specific gender populations.

Race

There is no FDA guidance on the use of Flutamide with respect to specific racial populations.

Renal Impairment

There is no FDA guidance on the use of Flutamide in patients with renal impairment.

Hepatic Impairment

There is no FDA guidance on the use of Flutamide in patients with hepatic impairment.

Females of Reproductive Potential and Males

There is no FDA guidance on the use of Flutamide in women of reproductive potentials and males.

Immunocompromised Patients

There is no FDA guidance one the use of Flutamide in patients who are immunocompromised.

Administration and Monitoring

Administration

• Oral

• Intravenous

Monitoring

There is limited information regarding Monitoring of Flutamide in the drug label.

• Description

IV Compatibility

There is limited information regarding IV Compatibility of Flutamide in the drug label.

Overdosage

Acute Overdose

Signs and Symptoms

• Description

Management

• Description

Chronic Overdose

There is limited information regarding Chronic Overdose of Flutamide in the drug label.

Pharmacology

File:Flutamide wiki.png

Mechanism of Action

• In animal studies, flutamide demonstrates potent antiandrogenic effects. It exerts its antiandrogenic action by inhibiting androgen uptake and/or by inhibiting nuclear binding of androgen in target tissues or both. Prostatic carcinoma is known to be androgen-sensitive and responds to treatment that counteracts the effect of androgen and/or removes the source of androgen, e.g., castration. Elevations of plasma testosterone and estradiol levels have been noted following flutamide administration.

Structure

Flutamide Capsules USP contain flutamide, an acetanilid, nonsteroidal, orally active antiandrogen having the chemical name, α,α,α-Trifluoro-2-methyl-4’-nitro-m-propionotoluidide and has the following structural formula:

File:Flutamide Structural Formula.jpg

C11H11F3N2O3 M.W. 276.21

Flutamide is a buff to yellow powder. Each capsule, for oral administration, contains 125 mg flutamide and has the following inactive ingredients: black iron oxide, corn starch, D&C yellow #10 aluminum lake, FD&C blue #1 aluminum lake, FD&C blue #2 aluminum lake, FD&C red #40 aluminum lake, gelatin, lactose monohydrate, magnesium stearate, red iron oxide, sodium lauryl sulfate, titanium dioxide and yellow iron oxide.

Pharmacodynamics

There is limited information regarding Pharmacodynamics of Flutamide in the drug label.

Pharmacokinetics

Absorption

Analysis of plasma, urine, and feces following a single oral 200 mg dose of tritium-labeled flutamide to human volunteers showed that the drug is rapidly and completely absorbed. Following a single 250 mg oral dose to normal adult volunteers, the biologically active alpha-hydroxylated metabolite reaches maximum plasma concentrations in about 2 hours, indicating that it is rapidly formed from flutamide. Food has no effect on the bioavailability of flutamide.

Distribution

In male rats neither flutamide nor any of its metabolites is preferentially accumulated in any tissue except the prostate after an oral 5 mg/kg dose of 14C-flutamide. Total drug levels were highest 6 hours after drug administration in all tissues. Levels declined at roughly similar rates to low levels at 18 hours. The major metabolite was present at higher concentrations than flutamide in all tissues studied. Following a single 250 mg oral dose to normal adult volunteers, low plasma levels of flutamide were detected. The plasma half-life for the alpha-hydroxylated metabolite of flutamide is about 6 hours. Flutamide, in vivo, at steady-state plasma concentrations of 24 to 78 ng/mL, is 94% to 96% bound to plasma proteins. The active metabolite of flutamide, in vivo, at steady-state plasma concentrations of 1556 to 2284 ng/mL, is 92% to 94% bound to plasma proteins.

Metabolism

The composition of plasma radioactivity, following a single 200 mg oral dose of tritium-labeled flutamide to normal adult volunteers, showed that flutamide is rapidly and extensively metabolized, with flutamide comprising only 2.5% of plasma radioactivity 1 hour after administration. At least 6 metabolites have been identified in plasma. The major plasma metabolite is a biologically active alpha-hydroxylated derivative which accounts for 23% of the plasma tritium 1 hour after drug administration. The major urinary metabolite is 2-amino-5-nitro-4-(trifluoromethyl)phenol.

Excretion

Flutamide and its metabolites are excreted mainly in the urine with only 4.2% of the dose excreted in the feces over 72 hours.

File:Flutamide pk.png

Special Populations

Geriatric

Following multiple oral dosing of 250 mg t.i.d. in normal geriatric volunteers, flutamide and its active metabolite approached steady-state plasma levels (based on pharmacokinetic simulations) after the fourth flutamide dose. The half-life of the active metabolite in geriatric volunteers after a single flutamide dose is about 8.1 hours and at steady state in 9.6 hours.

Race

There are no known alterations in flutamide absorption, distribution, metabolism, or excretion due to race.

Renal Impairment

Following a single 250 mg dose of flutamide administered to subjects with chronic renal insufficiency, there appeared to be no correlation between creatinine clearance and either Cmax or AUC of flutamide. Renal impairment did not have an effect on the Cmax or AUC of the biologically active alpha-hydroxylated metabolite of flutamide. In subjects with creatinine clearance of < 29 mL/min, the half-life of the active metabolite was slightly prolonged. Flutamide and its active metabolite were not well dialyzed. Dose adjustment in patients with chronic renal insufficiency is not warranted.

Hepatic Impairment

No information on the pharmacokinetics of flutamide in hepatic impairment is available (see BOXED WARNINGS, Hepatic Injury).

Women, Pediatrics

Flutamide has not been studied in women or pediatric patients.

Drug-Drug Interactions

Interactions between flutamide capsules and LHRH agonists have not occurred. Increases in prothrombin have been noted in patients receiving warfarin therapy (see PRECAUTIONS).

Clinical Studies

Flutamide has been demonstrated to interfere with testosterone at the cellular level. This can complement medical castration achieved with LHRH agonists which suppresses testicular androgen production by inhibiting luteinizing hormone secretion.

The effects of combination therapy have been evaluated in two studies. One study evaluated the effects of flutamide and an LHRH agonist as neoadjuvant therapy to radiation in stage B2-C prostatic carcinoma and the other study evaluated flutamide and an LHRH agonist as the sole therapy in stage D2 metastatic carcinoma.

Stage B2-C Prostatic Carcinoma

The effects of hormonal treatment combined with radiation were studied in 466 patients (231 flutamide capsules + goserelin acetate implant + radiation, 235 radiation alone) with bulky primary tumors confined to the prostate (stage B2) or extending beyond the capsule (stage C), with or without pelvic node involvement.

In this multicentered, controlled trial, administration of flutamide capsules (250 mg t.i.d.) and goserelin acetate (3.6 mg depot) prior to and during radiation was associated with a significantly lower rate of local failure compared to radiation alone (16% vs. 33% at 4 years, P < 0.001). The combination therapy also resulted in a trend toward reduction in the incidence of distant metastases (27% vs. 36% at 4 years, P = 0.058). Median disease-free survival was significantly increased in patients who received complete hormonal therapy combined with radiation as compared to those patients who received radiation alone (4.4 vs. 2.6 years, P < 0.001). Inclusion of normal PSA level as a criterion for disease-free survival also resulted in significantly increased median disease-free survival in patients receiving the combination therapy (2.7 vs. 1.5 years, P < 0.001).

Stage D2 Prostatic Carcinoma

To study the effects of combination therapy in metastatic disease, 617 patients (311 leuprolide + flutamide, 306 leuprolide + placebo) with previously untreated advanced prostatic carcinoma were enrolled in a large multicentered, controlled clinical trial.

Three and one-half years after the study was initiated, median survival had been reached. The median actuarial survival time was 34.9 months for patients treated with leuprolide and flutamide versus 27.9 months for patients treated with leuprolide alone. This 7 month increment represents a 25% improvement in overall survival time with the flutamide therapy. Analysis of progression-free survival showed a 2.6 month improvement in patients who received leuprolide plus flutamide, a 19% increment over leuprolide and placebo.

Nonclinical Toxicology

There is limited information regarding Nonclinical Toxicology of Flutamide in the drug label.

Clinical Studies

There is limited information regarding Clinical Studies of Flutamide in the drug label.

How Supplied

Storage

There is limited information regarding Flutamide Storage in the drug label.

Images

Drug Images

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Package and Label Display Panel

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Patient Counseling Information

There is limited information regarding Patient Counseling Information of Flutamide in the drug label.

Precautions with Alcohol

• Alcohol-Flutamide interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

Brand Names

Eulexin

Look-Alike Drug Names

• A® — B®

Drug Shortage Status

Price

References

The contents of this FDA label are provided by the National Library of Medicine.

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