Gefitinib has rarely caused very serious (possibly fatal) liver disease. Get medical help right away if you develop symptoms of liver disease, including stomach/abdominal pain, extreme fatigue, dark urine, yellowing eyes/skin.
Gefitinib has also rarely caused very serious (possibly fatal) holes in the wall of the stomach or intestines. Get medical help right away if you develop stomach/abdominal pain, black/bloody stools, or vomit that looks like coffee grounds.
Take gefitinib by mouth once daily, with or without food, or as directed.
Medications which reduce or completely block stomach acid (e.g., proton pump inhibitors/PPIs, H2 blockers, antacids) may decrease the absorption of gefitinib. This could decrease the effectiveness of gefitinib. Consult your doctor or pharmacist if you are taking any of these medications.
Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same time each day.
See also Warning section.
Diarrhea, rash, acne, nausea, vomiting, loss of appetite, nail problems, hair loss, red/sore mouth or throat, or unusual weakness may occur. If any of these effects persist or worsen, notify your doctor or pharmacist right away.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Persistent nausea, vomiting, diarrhea, or loss of appetite may result in a serious loss of body water (dehydration) and kidney problems. Contact your doctor promptly if you notice any symptoms of dehydration, such as: unusual decreased urination, unusual dry mouth/thirst, fast heartbeat, dizziness/lightheadedness.
If you have persistent diarrhea or skin rashes contact your doctor. Your doctor may temporarily stop gefitinib (for up to 14 days) which may help reverse those side effects. Treatment is then resumed with the same dosage.
An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include: severe rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: lung disease (e.g., pulmonary fibrosis), severe kidney disease, eye problems, stomach/intestinal ulcers, other stomach/intestinal problems (such as diverticulitis, blockage, bowel disease), smoking, cancer that has spread to the bowels.
Gefitinib is not recommended for use during pregnancy. It may cause harm to an unborn baby. Consult your doctor for more details.
It is not known whether this drug passes into breast milk. Due to the potential risk to the infant, breast-feeding while using gefitinib is not recommended.
See also How to Use section.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription products you may use, especially of: "blood thinners" (warfarin), drugs which reduce stomach acid (e.g., ranitidine, cimetidine, famotidine, omeprazole, lansoprazole, rabeprazole), certain liver enzyme inhibitors (CYP 3A4 inhibitors such as ketoconazole, itraconazole, erythromycin, clarithromycin), vinorelbine, NSAIDs (such as ibuprofen, naproxen), corticosteroids (such as prednisone).
Some liver enzyme inducer medications such as rifamycins (e.g., rifampin, rifabutin), St. John's wort or phenytoin will stimulate certain liver enzymes (CYP 3A4). Your dosage of gefitinib may need to be increased if you are using such medications. Consult your doctor or pharmacist for more details.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe/persistent diarrhea, severe skin rash.
Do not share this medication with others.
Laboratory and/or medical tests (such as kidney/liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, use it as soon as you remember. If it is less than 12 hours before the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature between 68 and 77 degrees F (20-25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised July 2016. Copyright(c) 2016 First Databank, Inc.
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