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Gefitinib

Generic name: gefitinib [ ge-FI-ti-nib ]
Brand name: Iressa
Dosage form: oral tablet (250 mg)
Drug class: EGFR inhibitors

Medically reviewed by Drugs.com on Dec 11, 2023. Written by Cerner Multum.

What is gefitinib?

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

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

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

Gefitinib may also be used for purposes not listed in this medication guide.

Gefitinib side effects

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

Gefitinib may cause serious side effects. Call your doctor at once if you have:

Common side effects of gefitinib may include:

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.

Warnings

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.

Before taking this medicine

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

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

Do not use gefitinib if you are pregnant. It could harm the unborn baby. Use effective birth control to prevent pregnancy while you are using gefitinib 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 gefitinib.

How should I use gefitinib?

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

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 gefitinib with or without food.

To make swallowing easier:

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

Store at room temperature away from moisture and heat.

Gefitinib dosing information

Usual Adult Dose for Non-Small Cell Lung Cancer:

250 mg orally once a day until disease progression or unacceptable toxicity

NOTE: For patients who have difficulty swallowing tablets immerse the tablet in 4 to 8 ounces of water (noncarbonated) and stir until dispersed (about 15 minutes). Drink the liquid or administer through a nasogastric tube. Rinse the container with 4 to 8 ounces of water and drink or administer through nasogastric tube.

Comments:
-Select patients for the first-line treatment of metastatic NSCLC with this drug based on the presence of EGFR exon 19 deletions or exon 21 L858R mutations in their tumor or plasma specimens.

Use: For first-line treatment of metastatic non-small cell lung cancer (NSCLC) in patients 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 gefitinib?

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

What other drugs will affect gefitinib?

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 this medication only for the indication prescribed.

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