Flutamide

A to Z Drug Facts

Flutamide

	Actions
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

FLEW-tuh-mide

Eulexin

Capsules for oral use

125 mg

Class: Antiandrogen

Antineoplastic hormone

Actions Flutamide inhibits androgen uptake or inhibits nuclear binding of androgen in target tissues or both. The plasma half-life for this metabolite is » 6 hr. Flutamide is 94% to 96% bound to plasma proteins. Flutamide and its metabolites are excreted mainly in the urine.

Indications Metastatic prostate cancer, combination therapy with a luteinizing hormone-releasing hormone analog (eg, goserelin, leuprolide).

Treatment of hirsutism in women (250 mg/day).

Contraindications Patients with severe hepatic impairment.

Route/Dosage

Prostate Cancer

ADULTS: PO 250 mg (2 capsules) q 8 hr.

Stage B₂-C Prostatic Carcinoma

ADULTS: PO Treatment should start 8 wk prior to initiating radiation therapy and continue during radiation therapy.

Stage D₂ Metastatic Carcinoma

ADULTS: PO Initiate flutamide capsules with the LHRH agonist and continue until progression.

Interactions Prothrombin time may increase when flutamide therapy is initiated in patients stabilized on chronic warfarin therapy.

Lab Test Interferences Elevated AST, ALT, bilirubin, SGGT, BUN, and serum creatinine.

Adverse Reactions

CNS: Decreased libido. ENDOCRINE: Hot flashes, gynecomastia. GI: Low potential for nausea and vomiting; diarrhea; hepatocellular necrosis; cholestatic jaundice; elevated LFTs. GU: Impotence; reduced sperm count.

Precautions

Pregnancy: Category D. Aniline exposure: A metabolite of flutamide, 4-nitro-3-fluoro-methylaniline, may cause methemoglobinemia, hemolytic anemia, and cholestatic jaundice in patients treated with flutamide. Hepatic injury: Hospitalization and rarely death from liver failure. 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 50% of the reported cases occurred within the initial 3 mo of treatment. Women: Flutamide is for use only in men.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Store capsules in refrigerator or at room temperature; protect from moisture.
For PO administration.
For patients unable to swallow capsules, open the capsule and mix the contents with applesauce, pudding, or other semi-solid foods. Administer immediately.

Assessment/Interventions

Monitor serum transaminase levels at baseline and monthly during the first 4 mo of treatment. Monitor periodically during continued treatment, especially if the patient experiences signs and symptoms of liver dysfunction. Immediately discontinue flutamide if ALT increases > 2 times above the upper limit of normal.
Monitor methemoglobin levels in patients susceptible to aniline toxicity (eg, people with glucose-6-phosphate dehydrogenase deficiency or hemoglobin M disease as well as patients who smoke).
Regular assessment of serum prostate specific antigen (PSA) may be helpful in monitoring the patient's response.

OVERDOSAGE: SIGNS & SYMPTOMS
	Hypoactivity; piloerection; slow respiration; ataxia; lacrimation; anorexia; tranquilization; emesis; methemoglobinemia

Patient/Family Education

The urine was noted to change to an amber or yellow-green appearance.
Photosensitization may occur.
Flutamide and LHRH-agonists should be administered concomitantly; and do not interrupt dosing or stop taking these medications without consulting the health care provider.