Gefitinib (Iressa) is an EGFR inhibitor used to treat non-small cell lung cancer (NSCLC). It’s only used when the tumor has a specific mutation in the EGFR gene, which can be detected with a certain test. Gefitinib (Iressa) is convenient to take because you take it by mouth, but it can have some side effects such as acne-like rash and diarrhea.
Metastatic non-small cell lung cancer (NSCLC) with specific EGFR mutations
Some NSCLC cancers are caused by changes in the EGFR gene. Gefitinib (Iressa) targets and blocks certain proteins from attaching to a specific receptor called EGFR. When gefitinib (Iressa) blocks EGFR, cancer cells can’t grow and spread as well.
Source: DailyMed
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Only taken once a day
Taken by mouth, so good for people who don’t like needles
Works in a more specific, targeted way than traditional chemotherapy
Recommended treatment option for patients with NSCLC and certain EGFR mutations
Can be taken with or without food
Commonly causes acne-like skin rash on the face and body
Need to separate from heartburn medications by 6 to 12 hours
Can cause ongoing, severe diarrhea
Can't take during pregnancy or breastfeeding
Ask your provider about starting medications to prevent the acne-like rash as soon as you start gefitinib (Iressa), as this can help lessen the severity of the rash
Taking heartburn medications like omeprazole (Prilosec) or antacids with gefitinib (Iressa) at the same time can cause gefitinib (Iressa) to not work as well in treating your cancer. If you need to take a heartburn medication, let your provider or pharmacist know. They might recommend that you separate your heartburn medication from gefitinib (Iressa) by 6 to 12 hours, depending on what kind you're taking, to avoid this interaction.
If you have difficulty swallowing solids, let your provider know. They can give you instructions on how to make an oral solution from your gefitinib (Iressa) tablet. Typically, you can drop the gefitinib (Iressa) tablet in 4-8 ounces of water in a cup and stir for about 15 minutes. Immediately drink the liquid. Then, swirl the cup with another 4-8 ounces of water and drink again.
Sometimes, taking gefitinib (Iressa) can cause your liver to become irritated. Most of the time, you won't feel any noticeable symptoms. But your provider can see signs of this through blood tests. Make sure you continue to get regular blood tests while you're taking gefitinib (Iressa) so your provider can check your liver health and make sure it's still safe for you to keep taking this medication. If you have stomach pain, yellowish skin, or yellow around the whites of your eyes, call your provider right away.
Don't breastfeed if you're taking gefitinib (Iressa). Animal studies suggest the medication can pass into breast milk. Because of the risk of harm to the nursing infant, it’s best to avoid nursing if you’re taking gefitinib (Iressa).
Ask your provider about the best way to handle and throw away gefitinib (Iressa) safely. Anticancer medications can be harmful to people who handle or come in contact with them. You should store the medication up and away, so children and pets won’t be able to reach it.
Gefitinib (Iressa) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Though rare, some people taking gefitinib (Iressa) have experienced a serious lung problem called interstitial lung disease (ILD). Talk to your provider right away if you experience sudden or worsening cough, trouble breathing , and fever. You might have to pause or stop gefitinib (Iressa) while your provider figures out the cause.
Risk factor: History of liver problems
Your doctor will monitor your liver health on a regular basis when you start gefitinib (Iressa). This is because some people taking gefitinib (Iressa) have shown higher levels of liver enzymes on their blood tests, which can suggest liver problems. Most people don’t feel any noticeable symptoms when this happens, so it’s important to keep up with your lab work regularly. If your liver enzyme level keeps going up, your provider might ask you to pause or stop the gefitinib (Iressa) while they look into it. If you have noticeable symptoms of liver problems, such as stomach pain, yellowish skin, or yellow around the whites of your eyes, call your provider right away.
Risk factor: History of stomach ulcers or other gut problems | Taking certain medications that can raise your risk for stomach tears, like aspirin or ibuprofen (Advil)
While very rare, gefitinib (Iressa) can cause tears in the lining of the stomach, intestines, or bowel (gastrointestinal perforation). Seek medical help right away if you experience sudden or severe stomach pain, fever, chills, nausea, or vomiting. If you develop a tear in the lining of your gut, you’ll have to stop taking gefitinib (Iressa).
Though not common, some people taking gefitinib (Iressa) have had severe diarrhea that is difficult to stop. Let your provider know if you have severe diarrhea (more than 7 bowel movements more than what’s normal for you in one day) or diarrhea that continues for two weeks because they might tell you to pause or stop taking gefitinib (Iressa). Your provider might also give you tips on how to manage less severe diarrhea at home with over-the-counter medications, like loperamide (Imodium-AD), and by eating bland foods and drinking lots of fluids.
Gefitinib (Iressa) can cause unusual eyelash growth, eyelid swelling, swelling of the tissue around your eyes, and dry eyes. Tell your provider if you have any vision changes while taking gefitinib (Iressa) because you might need to pause or stop taking this medication.
Mild rashes are common and usually not serious for people taking gefitinib (Iressa). But rarely, this medication can also cause serious skin problems, including severe skin reactions or infections that can be life-threatening, such as Stevens-Johnson syndrome. Tell your provider right away if you develop painful blisters, skin wounds, or peeling skin as these are signs of a serious skin reaction that need immediate medical attention.
Based on animal studies, gefitinib (Iressa) might harm an unborn baby or raise the risk for miscarriage (pregnancy loss). Because of these risks, if you’re a female who can get pregnant, you should use birth control while taking gefitinib (Iressa) and for two weeks after the last dose. Let your provider know right away if you become pregnant while taking gefitinib (Iressa).
The usual dose of gefitinib (Iressa) is 250 mg by mouth once a day.
Metastatic non-small cell lung cancer (NSCLC) with specific EGFR mutations
Metastatic non-small cell lung cancer (NSCLC) in certain adults
Advanced, unresectable, or metastatic pancreatic cancer, in combination with gemcitabine (Gemzar)
Metastatic NSCLC that have non-resistant mutations in the EGFR gene
Metastatic squamous NSCLC that’ve gotten worse after receiving platinum therapy
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American Cancer Society. (2019). Chemotherapy safety.
American Lung Association. (n.d.). Interstitial lung disease (ILD).
Hafner, J., et al. (2023). Intestinal perforation. StatPearls.
Ingenus Pharmaceuticals, LLC. (2023). Gefitinib tablet, coate [package insert]. DailyMed.
Lacouture, M. E. (2013). Prevention and treatment of acneiform rash caused by EGFR inhibitors. The American Society of Clinical Oncology Post.
Lacouture, M. E., et al. (2011). Clinical practice guidelines for the prevention and treatment of EGFR inhibitor-associated dermatologic toxicities. Supportive Care in Cancer.
National Cancer Institute. (n.d.). EGFR gene.
National Cancer Institute. (2023). Non-small cell lung cancer treatment (PDQ®)–Patient version.
National Comprehensive Cancer Network. (2023). Metastatic non-small cell lung cancer.
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