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Gefitinib Dosage

Medically reviewed by Last updated on Dec 21, 2018.

Applies to the following strengths: 250 mg

Usual Adult Dose for Non-Small Cell Lung Cancer

250 mg orally once a day

Duration of therapy: Until disease progression or unacceptable toxicity

-Information on FDA-approved tests for detection of EGFR mutations in NSCLC:

Use: First-line treatment of metastatic non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations as detected by an FDA-approved test.

Renal Dose Adjustments

No adjustment recommended; data not available in patients with severe renal impairment.

Liver Dose Adjustments

No adjustment recommended; use with caution in patients with moderate to severe hepatic impairment due to possible increase in systemic exposure.

Hepatotoxicity During Treatment:
-Withhold treatment in patients with worsening liver function.
-Permanently discontinue treatment in patients with severe hepatic impairment.

Dose Adjustments

Withhold Treatment (up to 14 days) for the following adverse drug reactions and then
Resume Treatment (250 mg orally once a day) when the adverse reaction fully resolves or improves to NCI CTCAE Grade 1:
-Acute onset or worsening of pulmonary symptoms (dyspnea, cough, fever)
-NCI CTCAE Grade 2 or higher in ALT and/or AST elevations
-NCI CTCAE Grade 3 or higher diarrhea
-Signs and symptoms of severe or worsening ocular disorders including keratitis
-NCI CTCAE Grade 3 or higher skin reactions

Permanently Discontinue Treatment for any of the following:
-Confirmed interstitial lung disease (ILD)
-Severe hepatic impairment
-Gastrointestinal perforation
-Persistent ulcerative keratitis

Concomitant Use with Strong CYP450 3A4 Inducer:
Avoid concomitant use if possible. If concomitant use is required:
-Increase dose to 500 mg orally once a day (in the absence of severe adverse drug reaction); resume at 250 mg dose 7 days after discontinuation of the strong CYP450 3A4 inducer.

Concomitant Use with Proton-Pump Inhibitor/H2-Receptor Antagonist/Antacid:
Avoid concomitant use if possible. If concomitant use is required:
-Take this drug 12 hours after the last dose of the proton-pump inhibitor or 12 hours before the next dose of the proton-pump inhibitor.
-Take this drug 6 hours after the last dose of the H2-receptor antagonist or antacid, or 6 hours before the next dose of the H2-receptor antagonist or antacid.


Safety and efficacy have not been established in patients younger than 18 years.

The safety and efficacy have not been established in patients with metastatic NSCLC whose tumors have EGFR mutations other than exon 19 deletions or exon 21 (L858R) substitution mutations.

Consult WARNINGS section for additional precautions.


Data not available.

Other Comments

Administration Advice:
-This drug should be taken at about the same time each day, with or without food.
-A missed dose should not be taken within 12 hours of the next dose.
-For patients who have difficulty swallowing solids, the manufacturer product information should be consulted for information on administering this drug as a dispersion in non-carbonated water.
-Treatment should be initiated and supervised by a physician experienced in the use of anticancer therapies.

Storage Requirements:
-Store in the original package to protect from moisture.

-Combination Cytotoxic Therapy: This drug combined with doublet, platinum-based cytotoxic chemotherapy in advanced NSCLC provides no added benefit over the cytotoxic chemotherapy alone. Thus, this drug should only be used as monotherapy in advanced NSCLC in patients who have previously received treatment with cytotoxic chemotherapy. (AU)
-EGFR Mutation Assessment: A well-validated and robust methodology should be chosen to assess the mutation status of a patient to minimize the possibility of false negative or false positive determinations. In the first-line setting, this drug should not be used in preference to doublet chemotherapy in mutation-negative patients. (AU)
-EGFR Mutation Assessment: This assessment should be attempted for all patients. If a tumor sample is not available for evaluation, then circulating tumor DNA (ctDNA) obtained from a blood (plasma) sample may be used. Only robust, reliable, and sensitive tests with demonstrated ability for the determination of EGFR mutation status of tumors or ctDNA should be used to avoid false negatives or false positive determinations. (UK)

-Hepatic: Liver function testing (periodically during treatment)
-Gastrointestinal: Urea, electrolytes, serum creatinine (in patients at high risk of dehydration)
-Hematologic: INR and PT (in patients concurrently taking warfarin)
-Ocular: Signs/symptoms of ocular disorder (e.g., acute or worsening eye inflammation, lacrimation, light sensitivity, blurred vision, eye pain, red eye)
-Respiratory: Acute onset or worsening of ILD-like symptoms (e.g., dyspnea, cough, fever)

Patient Advice:
-If you take a proton pump inhibitor (PPI), H2 blocker, or antacid medication, talk to your healthcare provider about the best time to take it during treatment with this drug.
-If you miss a dose and it is LESS than 12 hours until your next dose, skip the missed dose. Otherwise, take the missed dose as soon as you remember. Do not take a double dose (2 doses at the same time) to make up for a forgotten dose.
-If you have difficulty swallowing solids, talk to your healthcare provider for special instructions on how to take this drug tablet.
-This drug may cause side effects such as unusual physical weakness that can affect your ability to perform certain activities; avoid driving and activities such as operating machinery until you know how this drug affects you.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.