• First-line treatment of patients with metastatic non–small-cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations.

Contraindicated in:

• Hypersensitivity
• OB: Pregnancy
• Lactation: Lactation.

Use Cautiously in:

• Idiopathic pulmonary fibrosis (↑ risk of pulmonary toxicity)
• Women of reproductive potential
• Pedi: Safety and effectiveness not established in children.

Derm: rash, alopecia, ERYTHEMA MULTIFORME, pruritus, STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS.

EENT: aberrant eyelash growth, blepharitis, conjunctivitis, corneal erosion/ulcer, dry eye, nose bleeding.

F and E: dehydration.

GI: anorexia, diarrhea, nausea, vomiting, dry mouth, GI PERFORATION, HEPATOTOXICITY, mouth ulceration.

GU: ↓ fertility (females), ↑ serum creatinine, hematuria.

Metab: weight loss.

Resp: dyspnea, INTERSTITIAL LUNG DISEASE.
Misc: fever, (INCLUDING ANGIOEDEMA)HYPERSENSITIVITY REACTIONS .

Drug-Drug:

• Strong CYP3A4 inducers, including rifampin and phenytoin, ↓ blood levels and effects (↑ dose of gefitinib to 500 mg/day).
• Strong CYP3A4 inhibitors, including ketoconazole and itraconazole, ↑ blood levels and effects.
• Absorption and effectiveness may be ↓ by drugs that ↑ gastric pH including H₂ receptor antagonists, proton pump inhibitors, and antacids; take gefitinib 12 hr after last dose or 12 hr before the next dose of proton pump inhibitor; take gefitinib 6 hr after last dose or 6 hr before next dose H₂ receptor antagonist or antacid.
• May ↑ risk of bleeding with warfarin.

(Generic available)

• Tablets: 250 mg;

• PO (Adults): 250 mg once daily; Concurrent use of rifampin or phenytoin: 500 mg once daily (resume 250 mg once daily dose 7 days after discontinuing strong CYP3A4 inducer).

Iressa

• Inhibits activation of kinases found in transmembrane cell surface receptors, including EGFR.

• Prolonged progression-free survival.

Therapeutic Classification: antineoplastics

Pharmacologic Classification: enzyme inhibitors

Absorption: 60% absorbed following oral administration.

Distribution: Extensively distributed.

Metabolism/Excretion: Primarily metabolized by the liver by the CYP3A4 isoenzyme, with some metabolism via the CYP2D6 isoenzyme; the CYP2D6 isoenzyme exhibits genetic polymorphism (7% of population may be poor metabolizers and may have significantly ↑ gefitinib concentrations and an ↑ risk of adverse effects). Primarily excreted in feces, with <4% excreted in urine.

Half-life: 48 hr.

(plasma levels)

• Instruct patient to take gefitinib as directed. Take missed doses up to 12 hrs of next dose. Advise patient to read the Instruction Sheet with each Rx refill; new information may be available.
• Advise patient to notify health care professional promptly if severe persistent diarrhea, nausea, vomiting, or anorexia occur; if shortness of breath or cough occur or worsen; or if eye irritation or other new symptoms develop.
• May cause fetal harm. Advise females of reproductive potential to use effective contraception during and for 2 wk after last dose, to avoid breastfeeding during therapy, and to notify health care professional if pregnancy is suspected. May impair fertility in females.

je-FIT-in-ib