Iressa

Generic name: gefitinib [ ge-FI-ti-nib ]
Drug class: EGFR inhibitors

Medically reviewed by Sophia Entringer, PharmD. Last updated on Nov 27, 2023.

What is Iressa?

Iressa is a cancer medication that interferes with the growth and spread of cancer cells in the body.

Iressa is used to treat non-small cell lung cancer.

Iressa is sometimes used to treat cancer that has spread to other parts of the body.

Warnings

Iressa should only be administered under the supervision of a qualified healthcare provider experienced in the use of cancer chemotherapeutic agents.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Serious side effects have been reported with the use of Iressa including: allergic reactions (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives); skin reactions/rash, lung problems; liver problems; eye problems; severe nausea, vomiting, loss of appetite, or diarrhea; and others. Talk to your doctor about the possible side effects from treatment with Iressa.

Before taking this medicine

You should not use Iressa if you are allergic to gefitinib.

To make sure Iressa is safe for you, tell your doctor if you have:

• liver disease;

• kidney disease;

• vision problems;

• breathing problems, lung disease other than lung cancer; or

• if you take a blood thinner (warfarin, Coumadin, Jantoven).

Do not use Iressa if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 2 weeks after your treatment ends.

This medicine may affect fertility (the ability to have children) in women. Tell your doctor if you plan to become pregnant.

It is not known whether gefitinib passes into breast milk or if it could harm a nursing baby. Do not breast-feed while taking Iressa.

How should I use Iressa?

Iressa should only be administered under the supervision of a qualified healthcare provider experienced in the use of cancer chemotherapeutic agent.

Your doctor will perform blood tests to make sure you have the correct tumor type to be treated with Iressa.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not use this medicine in larger or smaller amounts or for longer than recommended.

You may take Iressa with or without food.

To make swallowing easier:

• Place the tablet into a glass of water (4 to 8 ounces) and stir for about 15 minutes.

• Do not use any liquid other than water.

• Stir and drink this mixture right away. Do not save for later use.

• To make sure you get the entire dose, add 4 to 8 more ounces of water to the same glass, swirl gently and drink right away.

• This mixture may also be given through a nasogastric (NG) tube. Ask your healthcare provider for instructions.

While using Iressa, you may need frequent blood tests to check your liver function.

Store at room temperature away from moisture and heat.

Dosing information

Usual Adult Dose for Non-Small Cell Lung Cancer:

250 mg orally once a day

Duration of therapy: Until disease progression or unacceptable toxicity

Comments:
-Information on FDA-approved tests for detection of EGFR mutations in NSCLC: http://www.fda.gov/CompanionDiagnostics

Use: First-line treatment of metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations as detected by an FDA-approved test.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if your next dose is less than 12 hours away. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Iressa?

Avoid taking an antacid or stomach acid reducer (Nexium, Pepcid, Prevacid, Prilosec, Zantac, and others) within 6 to 12 hours before or 6 to 12 hours after you take Iressa. These other medicines can make gefitinib much less effective when taken at the same time.

Iressa side effects

Get emergency medical help if you have signs of an allergic reaction to Iressa: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• severe or ongoing diarrhea;

• sudden chest pain or discomfort, new or worsening cough with fever, trouble breathing;

• blurred vision, watery eyes, eye pain or redness, eyes being more sensitive to light;

• liver problems - nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes);

• signs of stomach bleeding - severe stomach pain, bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds; or

• severe skin reaction - fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

Common Iressa side effects may include:

• diarrhea;

• acne;

• increased liver enzymes;

• trouble sleeping, fatigue, weakness;

• dry skin, dry mouth; or

• itching or skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Iressa?

Other drugs may interact with gefitinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Iressa only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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