Health Library

Gefitinib (By mouth)

Gefitinib (ge-FI-ti-nib)

Treats lung cancer.

Brand Name(s):

Iressa

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Your doctor will tell you how much medicine to use. Do not use more than directed.
• If you cannot swallow the tablet, put it in 4 to 8 ounces of water and stir the mixture for 15 minutes to dissolve the tablet. Drink the liquid right away. Add another 4 to 8 ounces of water to the same container, and drink it right away.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: Take a dose as soon as you remember. If it is less than 12 hours until your next dose, skip the missed dose and take your regular dose at the usual time. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how gefitinib works. Tell your doctor if you are using any of the following:
  • Itraconazole, ketoconazole, phenytoin, rifampicin
  • Blood thinner (including warfarin)
  • Medicine to treat depression
  • Stomach medicine (including antacids, cimetidine, esomeprazole, famotidine, omeprazole)

Warnings While Using This Medicine:

• It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant. Use an effective form of birth control during treatment and for at least 14 days after your last dose.
• Tell your doctor if you are breastfeeding, or if you have liver disease, stomach or bowel problems, or a history of other lung disease.
• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• This medicine may cause the following problems:
  • Interstitial lung disease, which can cause breathing problems
  • Liver problems
  • Gastrointestinal perforation (hole in your stomach or bowel)
  • Eye problems
  • Serious skin reactions
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Blistering, peeling, or red skin rash
• Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes
• Eye redness or pain, vision changes, sensitivity to light
• New or worsening trouble breathing, fever, cough
• Severe diarrhea or diarrhea that does not go away
• Severe stomach pain, bloody or black stools, vomit that looks like coffee grounds

If you notice these less serious side effects, talk with your doctor:

• Mild rash or itching

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 9/6/2024