Iressa

gefitinib

(je-fit-in-ib) ,

Iressa

(trade name)

Classification

Therapeutic: antineoplastics
Pharmacologic: enzyme inhibitors
Pregnancy Category: D

Indications

Patients who are currently benefiting from or have benefited from gefitinib in the past for treatment of non–small-cell lung cancer.

Action

genetic implication Inhibits activation of kinases found in transmembrane cell surface receptors, including epidermal growth factor receptor (EGFR-TK).

Therapeutic effects

Death of rapidly replicating cells, particularly malignant ones.

Pharmacokinetics

Absorption: 60% absorbed following oral administration.
Distribution: Extensively distributed.
Metabolism and Excretion: Mostly metabolized by the liver (CYP3A4 enzyme system); excreted in feces, <4% excreted in urine.
Half-life: 48 hr.

Time/action profile

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Contraindications/Precautions

Contraindicated in: Hypersensitivity; Obstetric / Lactation / Pediatric: Pregnancy, lactation, children.
Use Cautiously in: Idiopathic pulmonary fibrosis (↑ risk of pulmonary toxicity);Concurrent use of strong inhibitors of the CYP3A4 enzyme system (may ↑ risk of toxicity).

Adverse Reactions/Side Effects

Central nervous system

  • weakness

Ear, Eye, Nose, Throat

  • aberrant eyelash
  • conjunctivitis
  • corneal erosion/ulcer
  • eye pain
  • ↓ vision

Cardiovascular

  • peripheral edema

Respiratory

  • pulmonary toxicity (life-threatening)
  • dyspnea

Gastrointestinal

  • diarrhea (most frequent)
  • nausea (most frequent)
  • vomiting (most frequent)
  • anorexia
  • hepatotoxicity
  • mouth ulceration

Dermatologic

  • acne (most frequent)
  • dry skin (most frequent)
  • rash (most frequent)
  • pruritus

Metabolic

  • weight loss

Miscellaneous

  • allergic reactions including angioedema (life-threatening)

Interactions

Drug-Drug interaction

Strong inducers of the CYP3A4 enzyme system, including rifampin and phenytoin, ↓ blood levels and effects (consider ↑ dose of gefitinib to 500 mg/day).Strong inhibitors of the CYP3A4 enzyme system, including ketoconazole and itraconazole, ↑ blood levels and effects (use with caution).Absorption and efficacy may be ↓ by drugs that ↑ gastric pH including cimetidine and ranitidine.May ↑ the risk of bleeding with warfarin.Concurrent use with vinorelbine may ↑ risk/severity of neutropenia.

Route/Dosage

Oral (Adults) 250 mg once daily.

Availability

Tablets: 250 mg

Nursing implications

Nursing assessment

  • Assess for signs of pulmonary toxicity (dyspnea, cough, fever). If interstitial lung disease is confirmed, discontinue gefitinib and treat appropriately.
  • Assess patient for eye symptoms such as pain during therapy. May require interruption of therapy and removal of aberrant eyelash. After symptoms and eye changes have resolved, may reinstate therapy.
  • Lab Test Considerations: Monitor liver function tests periodically. May cause ↑ transaminases, bilirubin, and alkaline phosphatase. Discontinue gefitinib if elevations are severe.
    • Monitor for changes in prothrombin time and INR in patients taking warfarin. May cause ↑ levels.

Potential Nursing Diagnoses

Diarrhea (Adverse Reactions)
Impaired skin integrity (Side Effects)
Ineffective breathing pattern (Adverse Reactions)

Implementation

  • Available only through the Iressa Access Program. Patients must be currently on the medication or in an approved study and must sign the Patient Consent Form. Physicians and prescribers must enroll in program.
  • Oral: Administer one tablet daily without regard to food. Tablets can also be dispersed in half a glass of drinking water (noncarbonated). No other liquids should be used. Drop the tablet in the water, without crushing it, stir until the tablet is dispersed (approximately 10 min), and drink the liquid immediately. Rinse the glass with half a glass of water and drink. The liquid can also be administered through a nasogastric tube.
    • May interrupt therapy briefly (14 days) for patients with poorly tolerated diarrhea with dehydration or skin adverse reactions. Follow by restarting 250 mg dose.

Patient/Family Teaching

  • Instruct patient to take gefitinib as directed. 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.
  • Instruct patient to notify health care professional if pregnancy is planned or suspected or if breast feeding.

Evaluation/Desired Outcomes

  • Decrease in size and spread of tumors in non–small-cell lung cancer.

Iressa

a trademark for gefitinib.
References in periodicals archive ?
The nation's largest independent specialty pharmacy will offer IRESSA (gefitinib) as a first-line treatment for selected patients with metastatic non-small cell lung cancer.
Contract award: drug delivery alimta - l01ba04, copaxone 20 mg / ml -: l03ax13, enbrel - l04ab01, humira - l04ab04, iressa 250 mg - l01xe02, simponi 50 mg - l04ab06, vectibix 20 mg / ml - l01xc08.
The FDA approval of our therascreen EGFR test with IRESSA is another highlight in QIAGEN's ongoing, successful collaboration with AstraZeneca.
One treatment on the NHS in England is a drug called Gefitinib - more commonly known as Iressa - to treat non-small cell lung cancer.
AstraZeneca ordered to pay damages over side effects of Iressa drug
Two of these medications, Tarceva and Iressa, target the cancer cells' epidermal growth factor receptor (EGF-Receptor) protein kinase to inhibit the growth of both lung cancer and brain cancer.
It says it is knocking down the cost of 30 tablets of the most popular drug - Iressa - to pounds 2,167.
AstraZeneca Plc's once-daily cancer pill Iressa has been approved for certain lung cancer patients in Europe, reviving the fortunes of a product that had until recently been largely written off by industry analysts.
Lung cancer patients who have acquired gene mutations associated with resistance to tyrosine kinase inhibitors such as Iressa or Tarceva can be identified far more accurately using a new mutation test kit from DxS.
The company was also forced to admit recently that its Iressa cancer treatment was unable to prolong the life of patients significantly.
25bn in the third quarter and counter the impact of weaker demand for other treatments including Iressa for cancer, which showed disappointing results in trials.
Iressa will still be available to those currently using it, but new patients have to qualify for strict clinical trials.