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Chemotherapy and other systemic treatment regimens may change due to COVID-19. Find out more at Systemic Treatment Regimens During COVID-19.


( ge-FI-tye-nib )
Exceptional Access Program
  • gefitinib - First-line monotherapy in locally advanced (not amenable to curative therapy) or metastatic NSCLC patients who have activating mutations of EGFR-TK, with specific criteria
Other Name(s): Iressa®
Appearance: tablet

Medication Information Sheet
gefitinib (ge-FI-tye-nib)
This document provides general information about your medication. It does not replace the advice of your health care professional. Always discuss your therapy with your health care professional and refer to the package insert for more details.

Other Name: Iressa®


What is this medication for?
  • For treating certain types of lung cancer and head and neck cancer.
What should I do before I have this medication?
  • Tell your doctor and pharmacist if you have/had significant medical condition(s), especially if you have / had lung, liver, kidney, eye problems, wear contact lenses, or have any allergies.
  • This drug contains a small amount of lactose. If you cannot tolerate lactose, talk to your doctor.
  • People with cancer have a higher risk of getting other cancers or developing blood clots. Some cancer medications may increase these risks, especially if used for a long period of time. Discuss any concerns about this medication with your health care team.
How will this medication affect sex, pregnancy and breastfeeding?
  • The use of this medication in men or women may cause harm to the unborn baby if pregnancy occurs. Let your health care team know if you or your partner is pregnant, becomes pregnant during treatment, or if you are breastfeeding
  • If there is ANY chance that you or your partner may become pregnant, you and your partner together must:  ►Use 2 effective forms of birth control at the same time while taking this drug: Keep using birth control until 6 months after the last dose (general recommendation). Discuss with your healthcare team.
  • Tell your doctor right away if you or your partner becomes pregnant.
  • Do not breastfeed while taking this drug.
  • Effects on Fertility: Probable
How is this medication given?
  • Gefitinib is usually taken once a day, at about the same time each day.
  • Take it exactly as directed by your doctor.
  • Swallow whole with a glass of water, with or without food.
  • If you miss a dose, take it only if there are at least 12 hours before the next dose is due. Otherwise, skip this and take the next dose as scheduled.  Do not double the dose to make up for the forgotten one.
  • Do not crush or chew the tablets.
What else do I need to know while on this medication?
  • Do not eat or drink grapefruit, starfruit, Seville oranges or their juices (or products that contain these) while on this treatment. They may increase side effects.

  • This medication can interact with other medications and can result in the treatment not working as well or cause severe side effects.

  • Make sure your health care team knows about all your medications (prescription, over-the-counter, herbals and supplements). Check with your health care team before starting or stopping any of them.

  • For mild aches and pain or fever:

    • If you feel unwell, take your temperature before taking any medications for pain or fever. They may hide a fever. 
    • You may take acetaminophen (Tylenol®) tablets. Ask your health care team about the right dose for you. 
    • Ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or aspirin (acetylsalicylic acid, ASA), including low dose aspirin for heart conditions, may increase your chance of bleeding. Talk to your health care team before you start or stop these medications.
    • Talk to your health care team or go to the closest emergency room right away if you have a fever.  See the Fever pamphlet for more information.
  • Drinking alcohol and smoking during your treatment may increase some side effects and make your medication less effective. Speak to your health care team about smoking and drinking alcohol while on treatment.

How should I safely store this medication?
  • Store in the original packaging at room temperature, away from heat, light or moisture. Keep out of reach of children and pets.
  • Do not throw out any unused drugs at home. Bring them to your pharmacy for safe disposal.


What are the side effects of this medication?

Common side effects usually occur in more than 1 out of every 10 patients. Other side effects are less common, but may be severe. You may not have all of the side effects below. You may have side effects that are not listed.

Side effects and what to do When to contact doctor?
More Common Side Effects

Rash; dry, itchy skin (may be severe in some cases)

  • Stay out of the sun; wear sunblock, a hat and cover exposed skin.
  • Use daily moisturizer.
  • May be severe, including blisters and skin peeling; get emergency medical help right away if this occurs.


Contact your health care team if no improvement or if severe

Diarrhea (may be severe in some cases)

  • Drink plenty of clear fluids. Limit hot, spicy, fried foods, foods/drinks with caffeine, orange or prune juice. Try a low-fiber BRAT diet (Bananas, white Rice, Apple sauce, Toast made with white bread).
  • Take anti-diarrhea drug(s) if given to you by your doctor.
  • Contact your doctor if diarrhea persists, or if you also have nausea/vomiting or are not eating/drinking well.
  • Also see Diarrhea pamphlet.*


Contact your health care team if no improvement or if severe

Poor Appetite; don't feel like eating; weight loss

  • Eat foods that you like and try to eat regular small meals.
  • Use meal supplements if possible.  See a dietitian.
Contact your health care team if no improvement or if severe

Nausea and vomiting (generally mild)

  • Drink clear fluids and avoid large meals. Get fresh air and rest.
  • Limit spicy, fried foods or foods with a strong smell.
  • Take anti-nausea drug(s) exactly as directed by your doctor. It is easier to prevent nausea than to treat it.
  • Contact your doctor if nausea lasts more than 48 hours or vomiting for more than 24 hours.
  • Also see Nausea & Vomiting pamphlet.*


Contact your health care team if no improvement or if severe

Trouble falling asleep

  • Talk to your doctor if this bothers you.
  • This may go away as your body gets used to the drug or when your treatment ends.
Contact your health care team if no improvement or if severe


  • Rest often; take naps if needed. Move slowly when getting up.
  • Eat well-balanced meals and drink plenty of fluids. Light exercise may help.
  • Do not drive a motor vehicle or operate machinery when feeling tired.
Contact your health care team if no improvement or if severe

Nail changes
(colour, pain, tenderness in nailbed, swelling of cuticles, loosening of nails)

  • Will slowly return to normal after treatment.
  • Use moisturizer for nails and cuticles. Avoid nail polish and artificial fingernails until your nails have returned to normal.
  • Wear gloves when doing house chores or gardening.
Contact your health care team if no improvement or if severe

Mouth sores

  • Maintain good mouth hygiene. Regular teeth brushing with a soft toothbrush or Toothette®, and regular use of alcohol-free mouthwashes.
  • Instead, try a homemade mouthwash: 
    Mix 1 teaspoonful of baking soda and 1 teaspoonful of salt in 4 cups (1L) of water.
  • Avoid hot, spicy, acidic, hard or crunchy foods.
  • Check with your doctor or nurse as soon as you notice sores in mouth/lips or pain with swallowing. Your doctor may prescribe a prescription mouthwash to relieve mouth sores and prevent infection.
  • Also see Mouth Care pamphlet.*
Contact your health care team as soon as possible

Abnormal liver lab tests (may rarely be severe)

  • Your doctor will monitor these regularly.  Call your doctor if you have yellowish skin or eyes, or unusual dark urine.
Contact your health care team if no improvement or if severe

Side effects and what to do When to contact doctor?
Less Common Side Effects, but may be Severe

Eye problems
(dry eyes, redness, irritation, pain, tearing, eyes sensitive to light, blurred vision or other unusual changes with your sight)

  • May try artificial tear drops or ointment to relieve dryness.


Contact your health care team as soon as possible

Unusual bleeding (coughing up blood, severe nosebleeds)

  • If nosebleed does not stop after 15 minutes, or coughing produces more than 1 teaspoonful (5 mL) of blood, or if you have chest pain, severe shortness of breath or dizziness, get emergency medical help right away.
Get emergency medical help right away

Kidney problems
(lower back pain, body swelling, passing little or no urine, or recent unusual weight gain)

  • May be caused by dehydration
Get emergency medical help right away

Lung problems
(increased cough, breathing problems, chest pain, coughing blood)

Get emergency medical help right away
Blockage of an artery (blood vessel) in your heart, brain, chest, belly, or limbs; this may result in stroke (sudden loss of vision, speech, or the use of your limb(s)) or heart attack (chest pain, shortness of breath), or pain in chest, belly or limb Get emergency medical help right away

Rupture in stomach or intestine wall
(Sudden, severe pain in belly or stomach area)

Get emergency medical help right away

Allergic reaction (severe rash, itchiness, swollen face, lip or tongue, chest or throat tightness; may occur during or shortly after the drug is given)

Get emergency medical help right away

Inflammation of blood vessels in the skin (red or purple patches on the skin, rash/patches that do not turn white when pressed)

Contact your health care team as soon as possible

Pancreas problems
(increased pain in centre of belly and may extend to back, appetite or weight loss)

Get emergency medical help right away

For more links on how to manage your symptoms go to

The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.

A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.