Gefitinib (Oral)


Gefitinib is a medicine that's available by prescription and is used for treating non-small cell lung cancer. It belongs to a class of medicines known as tyrosine kinase inhibitors. It's believed to work by thwarting the action of a naturally occurring substance thought to promote the growth and multiplication of cancer cells.

Gefitinib comes in the form of a tablet and is used once daily, with/without food. It's available under the Iressa brand name.

Some common Gefitinib side effects include skin changes, diarrhea, nausea, and eye problems.

Conditions Treated

  • Non-small cell lung cancer

Type Of Medicine

  • Tyrosine kinase inhibitor

Side Effects

Common Gefitinib side effects

Each person reacts differently to their treatment. Some people may develop more side effects, while others may develop very few. The side effects discussed below won't affect everybody having treatment with Gefitinib.

We've listed some of the most common effects but have not listed all of the rare ones as you're unlikely to be affected by them. If you develop any effects not listed below, please see your nurse or doctor.

Skin changes

The most common Gefitinib side effect is a rash that looks like acne that mainly attacks the back, chest, and head. This normally starts during the first two to three weeks of treatment with this medicine and disappears once your treatment ends.

Your skin may also get itchy and dry, or peel and feel tender.

There are certain things you can try in order to treat this problem, but they can't completely prevent it:

  • Don't use skincare products that contain alcohol.
  • Use non-scented, mild soap and tepid water for washing and bathing.
  • Avoid anti-acne products because they can make your skin dry and worsen your symptoms.
  • Regularly moisturize your skin, including after a shower or bath. Consult your specialist nurse or doctor to find out the best moisturizers.
  • Wear rubber gloves to shield your hands from detergent when washing dishes.
  • While you're in the sun, protect your skin as sunlight can worsen your symptoms. While receiving Gefitinib treatment, and for a number of months after treatment, you'll be more susceptible to sunlight and your skin can burn more easily than usual. If you still want to be in the sun, wear a sunscreen with a high SPF, and cover yourself with a hat and clothing. If you're receiving radiotherapy, don't use sunscreen in any area of your skin being treated.

Let your physician know at once if you have skin changes. He or she may prescribe medication to help treat you.

If you develop more effects, you can stop Gefitinib treatment for a number of days to let your skin recover.


Gefitinib may bring on diarrhea. This can normally be easily managed with medication, but tell your physician if it persists or it's severe. It's vital to take lots of fluids (about 4 pints/2 liters per day) if you suffer diarrhea.

Loss of appetite

While taking Gefitinib, you may experience loss of appetite. Try to regularly eat small meals. If your appetite fails to improve after a couple of days, alert your nurse or doctor. They can recommend a dietitian to give you advice. The dietitian may give you meal replacement drinks and food supplements to try. You can purchase some of these from pharmacies with your doctor's prescription.

Being sick or feeling sick (nausea and vomiting)

If you develop nausea and vomiting, you can control this by taking anti-emetic (anti-sickness) medicines that your healthcare professional may prescribe for you. If the symptoms don't improve, tell your doctor so he/she can prescribe other medications which can work better.

Dry/sore mouth

Your mouth can become sore, red, or dry. This may make you very likely to develop a mouth infection. Clean your dentures and teeth gently after meals, in the morning, and at night. Use a children's or soft-bristled toothbrush. You may be asked to use mouthwashes or regularly rinse your mouth. It's vital to follow any instructions given and take plenty of fluids.

If you have any issues with your mouth, notify your doctor or nurse. They may prescribe medication to treat or prevent infections of the mouth and relieve any soreness.


One common effect of any cancer medication is feeling tired. It's vital to try to set your pace and have as much of a breather as you need. You can balance this with some gentle workouts like short walks. If fatigue is making you drowsy, don't operate machinery or drive.

Nail and hair changes

You may discover that your body and head hair becomes more brittle, finer, or curlier. Some people suffer hair loss or hair thinning. These changes are normally short-term and gradually improve after you complete treatment.

The nails of your feet or hands may become sore and brittle, or red. If this happens, let your healthcare provider know. You can protect your nails by wearing gloves when washing dishes or using detergents.

Vision problems

Your eyes can feel sore or become dry, or become inflamed or red. Your doctor may prescribe eye drop medication to help treat these issues. If you develop vision changes or your eyes feel painful, notify your doctor at once.

Some people's eyelashes become longer and curlier than normal but this is not common.

Bladder irritation

You may suffer bladder irritation during treatment. You may have a burning sensation when you urinate, or you may feel like urinating more urgently or more often. If you've got these symptoms, notify your nurse or doctor. Drink a lot of fluids (about 4 pints/2 liters a day). In rare cases, you may have bloody urine. If you see this, tell your doctor promptly.

Liver changes

Gefitinib treatment may change how your liver functions, but it'll get back to normal once the treatment ends. Your healthcare provider will take your blood samples regularly to check if your liver is functioning properly.

Less common Gefitinib side effects

Breathing problems

This is a less common effect that can affect about 1% of people using Gefitinib.

If your breathing worsens, you become breathless or you have a fever or cough, notify your doctor promptly. It may be a sign that you have lung inflammation, which may be serious.

Bleeding problems

Let your healthcare provider know if you develop any unusual bleeding, such as bleeding gums, nosebleeds, or have bloody urine while using Gefitinib.

Severe stomach pain

Gefitinib may cause an inflamed pancreas or a perforation (hole) in the little bowel. Call up your physician at once if you suffer severe stomach pain and vomiting and nausea. It's also critical to tell them if you have black stools, bleeding from the anus, or if you're vomiting blood or something that resembles coffee grounds.

It's vital to notify your doctor at once if you feel sick or develop any severe effects, even if they aren't listed above.


Your healthcare provider will carry out blood tests to ensure you've got the right type of tumor to receive Gefitinib treatment.

Follow all instructions found on the prescription label. Your healthcare provider may occasionally alter your dose to ensure you get optimal results. Don't use Gefitinib in smaller or larger quantities or for a longer period than recommended.

  • You may take this medication with or without your meals.
  • To ensure that swallowing is easier, do the following:
  • Put the tablet in one glass of water (4-8 oz) and stir for around 15 minutes.
  • Only use water as a liquid.
  • Stir and take this mixture immediately. Don't keep it for later use.
  • To ensure you receive the full dose, refill the glass with water, gently swirl and drink straight away.
  • You can also take this mixture via a nasogastric tube (NG tube). Ask your healthcare professional for directions.
  • While taking Gefitinib, you may require blood tests frequently to examine your liver function.

While using Gefitinib, avoid taking a stomach acid reducer (e.g Zantac, Prilosec, Prevacid, Pepcid, Nexium, etc.) or an antacid within 6 hours after or before you take Gefitinib. These medications may make Gefitinib significantly less effective when used together.


Tell your healthcare provider about all sorts of drugs you use, such as prescription and over-the-counter medicines, herbal supplements, and vitamins. Especially let your healthcare provider know if you use:

Phenytoin or Rifampin (Dilantin) you may require a higher Gefinitib dose to ensure that Gefitinib remains effective.

Cimetidine or Ranitidine these medications raise gastric pH, leading to a decreased concentration of Gefitinib in the plasma. This can cause Gefitinib to be less effective.

Vinorelbine taking Vinorelbine alongside Gefitinib may increase your risk of getting a condition known as neutropenia. This refers to an unusually low level of neutrophils, which are white blood cells that assist your immune system to fend off infections.

Antifungals such as Voriconazole (Vfend), Ketoconazole (Nizoral), Itraconazole (Sporanox) you may require a lower Gefitinib dose to prevent the side effects brought on by higher levels of Gefitinib.

Blood thinners/anticoagulants e.g. Warfarin (Coumadin) Gefitinib can raise the blood thinning abilities of Warfarin and increase the chances of bleeding.

Gefitinib may interact with many other medicines, so make sure to report all the medicines you're using to your doctor, even those that don't appear on the above list. Your doctor may have to carefully monitor you for side effects or alter the doses of each medication you take.

If you eat grapefruit or take grapefruit juice regularly, report this to your doctor because grapefruit can interfere with Gefitinib.


Tell your physician as well as the pharmacist if you have allergies to Gefitinib, to some of its ingredients, or to any other medications.

Tell your physician and pharmacist what medications (prescription and nonprescription), nutritional supplements, and vitamins you're using or plan to use. Make sure to report any of these: blood thinners (anticoagulants) such as Warfarin (Jantoven, Coumadin); antifungals like Ketoconazole (Nizoral), Itraconazole (Sporanox, Onmel); Phenytoin (Phenytek, Dilantin); Metoprolol (Dutoprol, Toprol XL, Lopressor); and tricyclic antidepressants like Amitriptyline and Imipramine (Tofranil).

If you're using an H2 blocker medicine or antacid for treating indigestion, ulcers, or heartburn like Ranitidine (Zantac), Nizatidine (Axid), Famotidine (Pepcid), Cimetidine (Tagamet), take each at least six hours after or before taking Gefitinib.

If you're using any proton pump inhibitor medicine for indigestion, ulcers, or heartburn like Omeprazole (Prilosec), Lansoprazole (Prevacid), Esomeprazole (Nexium), Rabeprazole (AcipHex), or Pantoprazole (Protonix), take it about 12 hours after or before taking Gefitinib.

Tell your physician if you've ever had or have scarring of lungs (fibrosis) or other breathing or lung problems, vision or eye problems, or liver disease.

Report to your physician if you plan to get pregnant or are pregnant. Gefitinib can cause infertility in women. However, you should prevent pregnancy with birth control during your Gefitinib treatment and for 14 days after you stop using Gefitinib. If you get pregnant while using Gefitinib, call up your physician. This medication may harm an unborn child and raise the risk of miscarriage.

If you're breastfeeding, inform your doctor. You shouldn't breastfeed while using Gefitinib.

Before using Gefitinib, tell your pharmacist or doctor about your medical past, especially of severe kidney disease, lung disease (such as pulmonary fibrosis), stomach/intestinal ulcers, eye problems, or other intestinal/stomach problems (including bowel disease, blockage, diverticulitis), smoking, or cancer that's reached the bowel.


  • Keep all medications out of children's sight and reach.
  • Keep Gefitinib in a dry, cool area, away from direct light and heat.
  • Return any unwanted or unused Gefitinib tablets to your pharmacy or clinic for safe disposal.


Honor all your appointments with the lab and your doctor. Your doctor will arrange some lab tests to assess your response to Gefitinib (Iressa). If you have a dry cough at any time, a sudden difficulty with your breathing, or a high temperature, you must report it to your doctor at once so it can be examined.

Don't let anybody else take your Gefitinib tablets even if they have the same symptoms as yours. If you've got any questions about how your prescription is refilled, ask your pharmacist.

Gefitinib should be given only under the watch of a qualified doctor or healthcare professional with experience in using cancer chemotherapeutic substances.

If you take or purchase any other medications, consult a pharmacist to find out if they're suitable to take with Gefitinib. Avoid any preparations which have St John's Wort as it can make Gefitinib less effective.

If you're having dental treatment or an operation, always tell the healthcare professional attending to you which medications you're taking.

While using Gefitinib, you may experience serious side effects, including liver problems, lung problems, allergic reactions (e.g. closing of the throat, difficulty breathing, swelling of the face, lips, tongue, or hives), eye problems, vomiting, severe nausea, diarrhea, or loss appetite, etc. Please talk to your physician about the potential side effects of Gefitinib treatment.