Gefitinib (patient information)

Why this medication is prescribed

Gefitinib is used to treat non-small cell lung cancer in people who have already been treated with certain other chemotherapy medications and have not improved or whose condition has worsened. Gefitinib has not been shown to help people who have non-small cell lung cancer live longer. There are other medications that may help people who have non-small cell lung cancer live longer. Therefore, only people who have already taken gefitinib and benefited from the medication should continue to take it. People who have never taken gefitinib should start their treatment with a medication that is known to help patients with lung cancer live longer. Gefitinib is in a class of anti-cancer medications called epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. It works by blocking the action of a certain naturally occurring substance that may be needed to help cancer cells multiply.

How this medication should be used

Gefitinib comes as a tablet to take by mouth. It is usually taken with or without food once a day. Take gefitinib at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take gefitinib exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are unable to swallow the tablets, you may dissolve them in water. Place one tablet in a half a glass of plain, non-carbonated drinking water. Stir with a spoon for about 10 minutes until the tablet is dissolved. Do not use the spoon to crush the tablet. Drink the mixture right away. Rinse the glass with another half glass of water and drink the rinse water to be sure that you swallow all of the medication.

Gefitinib is not available in pharmacies. You can only get gefitinib through a distribution program that has been set up by the manufacturer for people who have taken gefitinib in the past. You will need to sign a consent form before you receive any medication. You will receive your medication by mail from a specific mail order pharmacy. Ask your doctor if you have any questions about receiving your medication.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Special precautions

Before taking gefitinib:

• tell your doctor and pharmacist if you are allergic to gefitinib or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention any of the following: anticoagulants ('blood thinners') such as warfarin (Coumadin); antifungals such as itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend); carbamazepine (Carbatrol, Equetro, Tegretol); amiodarone (Cordarone, Pacerone); clarithromycin (Biaxin); diltiazem (Cardizem, Dilacor, Tiazac); erythromycin (E.E.S, E-Mycin, Erythrocin); fluvoxamine (Luvox); medications for heartburn and ulcers such as cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid), and ranitidine (Zantac); metoprolol (Lopressor, Toprol XL); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); medications for human immunodeficiency virus (HIV) such as indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir, in Kaletra); nefazodone; phenobarbital; phenytoin (Dilantin); verapamil (Calan, Covera, Isoptin, Verelan); and vinorelbine (Navelbine). Many other medications may interact with gefitinib, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor what herbal products you are taking, especially St. John's wort.
• tell your doctor if you have or have ever had pulmonary fibrosis (scarring of the lungs), or liver or kidney disease.
• tell your doctor if you are pregnant or plan to become pregnant. You should use birth control to prevent pregnancy during your treatment with gefitinib and for some time after you stop using the medication. If you become pregnant while taking gefitinib, call your doctor. *Gefitinib may harm the fetus and increase the risk of pregnancy loss.
• tell your doctor if you are breast-feeding. You should not breast-feed while you are taking gefitinib.

Special dietary instructions

Talk to your doctor about eating grapefruit and drinking grapefruit juice while you are taking this medicine.

What to do if you forget a dose

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Side effects

Minor side effects

Gefitinib may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry skin
• itching
• rash
• acne
• mouth sores
• weight loss
• weakness

Severe side effects

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• new or worsening shortness of breath, cough, or fever
• diarrhea
• nausea
• vomiting
• loss of appetite
• eye pain, redness, or irritation
• change in vision
• growth of eyelashes on the inside of the eyelid
• hives
• swelling of the eyes, face, lips, tongue, throat, hands, arms, feet, ankles or lower legs

Gefitinib may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Storage conditions needed for this medication

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Symptoms of overdose may include:

• diarrhea
• rash

Other information

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to gefitinib.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Iressa®