FLUTAMIDE
(flu'ta-mide)
Eulexin
Classifications: antineoplastic; antiandrogen
Pregnancy Category: D

Availability

125 mg capsules

Actions

Nonsteroidal, nonhormonal, antiandrogenic that inhibits androgen uptake or binding of androgen to target tissues (i.e., prostatic cancer cells).

Therapeutic Effects

Interferes with the binding of both testosterone and dihydrotestosterone to target tissue (i.e., prostate cancer cells).

Uses

In combination with luteinizing hormone-releasing hormone agonists (i.e., leuprolide) or castration for early stage and metastatic prostate cancer.

Contraindications

Hypersensitivity to flutamide; severe liver impairment if ALT is equal to twice the normal value; pregnancy (category D), lactation.

Route & Dosage

Prostate Cancer
Adult: PO 250 mg (2 caps) q8h

Administration

Oral

Adverse Effects (1%)

CNS: Drowsiness, confusion, depression, anxiety, nervousness. GI: Diarrhea, nausea, vomiting, anorexia, hepatitis, cholestatic jaundice, encephalopathy, hepatic necrosis, acute hepatic failure, may increase ALT, AST, bilirubin. Urogenital: Hot flashes, loss of libido, impotence. Hematologic: Anemia, leukopenia, thrombocytopenia. Skin: Rash. Body as a Whole: Edema. Endocrine: Gynecomastia, galactorrhea.

Interactions

Drug: may increase INR in patients on warfarin.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Onset: Antiandrogenic activity 2.2 h; symptomatic relief 2–4 wk. Duration: 3 mo–2.5 y, with an average of 10.5 mo. Metabolism: Metabolized in liver to at least 10 different metabolites; the major metabolite, 2-hydroxyflutamide (SCH-16423), is an alpha-hydroxylated derivative that is biologically active. Elimination: 98% excreted in urine. Half-Life: 5–6 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug