flutamide

Therapeutic Classification: antineoplastics

Pharmacologic Classification: antiandrogens

Indications ⬆ ⬇

High Alert

Prostate cancer (in combination with a luteinizing hormone-releasing hormone [LHRH] agonist).

Action ⬆ ⬇

Antagonizes the effects of androgen (testosterone) at the cellular level.

Therapeutic effects:

Decreased growth of prostate carcinoma, an androgen-sensitive tumor.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed after oral administration.

Distribution: Unknown.

Metabolism/Excretion: Mostly metabolized by the liver. Some conversion to another antiandrogenic compound (2-hydroxyflutamide).

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Severe hepatic impairment.

Use Cautiously in:

Severe cardiovascular disease.

Adv. Reactions/Side Effects ⬆ ⬇

Side effects primarily caused by LHRH antagonist

CV: edema, hypertension

Derm: photosensitivity, rash

Endo: gynecomastia, hot flushes

GI: diarrhea, nausea, vomiting, HEPATOTOXICITY

GU: erectile dysfunction, loss of libido

Neuro: anxiety, confusion, drowsiness, mental depression, nervousness

Interactions ⬆ ⬇

Drug-drug:

Acts synergistically withLHRH analogues (leuprolide).

Route/Dosage ⬆ ⬇

PO (Adults ): 250 mg every 8 hr.

Availability ⬆ ⬇

(Generic available)

Capsules: 125 mg; 250 mg

Assessment ⬆ ⬇

Monitor for diarrhea, nausea, and vomiting. Adjust diet as tolerated. Notify health care professional if these symptoms become severe.

Lab Test Considerations:

May cause ↑ AST, ALT, bilirubin, and serum creatinine. Monitor ALT before therapy, monthly for the first 4 mo of therapy, and periodically thereafter. If ALT ↑ above 2 times the upper limit of normal, flutamide should be discontinued immediately. Liver function tests should also be obtained at the first sign of nausea, vomiting, abdominal pain, fatigue, anorexia, or hyperbilirubinemia.
- May cause ↑ plasma estradiol and testosterone concentrations.

Implementation ⬆ ⬇

Used in combination with LHRH agonist, such as leuprolide.
PO: Administer capsules three times/day, 8 hr apart.

Patient/Family Teaching ⬆ ⬇

Explain that flutamide must be taken in conjunction with leuprolide. Instruct patient to take flutamide exactly as directed. If a dose is missed, take as soon as possible unless almost time for next dose. Do not double doses.
Warn patient that side effects such as hot flashes, loss of sex drive, erectile dysfunction, and breast enlargement may be caused by the LHRH agonist. The primary side effect of flutamide alone is diarrhea, but the combination of drugs is necessary to achieve the therapeutic effect.
Advise patient to notify health care professional immediately if dark urine, itching, loss of appetite, nausea, vomiting, pain in right side, or yellow eyes or skin occurs. Hepatotoxicity usually resolves when flutamide is discontinued, but it may be progressive and fatal; requires immediate medical attention.

section name header

Pronunciation ⬇

Classifications ⬆ ⬇