In this article, we will discuss about Gefitinib (Dosage). So, let’s get started.
Indications
Gefitinib is indicated for the first-line treatment of patients with 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.
Limitation of Use: Safety and efficacy of Gefitinib 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.
Dosage
Patient Selection
Select patients for the first-line treatment of metastatic NSCLC with Gefitinib based on the presence of EGFR exon 19 deletions or exon 21 L858R mutations in their tumor or plasma specimens. If these mutations are not detected in a plasma specimen, test tumor tissue if feasible.
Recommended Dose
The recommended dose of Gefitinib is 250 mg orally once daily with or without food until disease progression or unacceptable toxicity.
Do not take a missed dose within 12 hours of the next dose.
Warnings and Precautions
• Interstitial lung disease (ILD): ILD occurred in patients taking Gefitinib. Withhold Gefitinib for worsening of respiratory symptoms. Discontinue Gefitinib if ILD is confirmed.
• Hepatotoxicity: Obtain periodic liver function testing. Withhold Gefitinib for Grade 2 or higher for ALT and/or AST elevations. Discontinue for severe hepatic impairment.
• Gastrointestinal perforation: Discontinue Gefitinib for gastrointestinal perforation.
• Diarrhea: Withhold Gefitinib for Grade 3 or higher diarrhea.
• Ocular Disorders including Keratitis: Withhold Gefitinib for signs and symptoms of severe or worsening ocular disorders including keratitis. Discontinue for persistent ulcerative keratitis.
• Bullous and Exfoliative Skin Disorders: Withhold Gefitinib for Grade 3 or higher skin reactions or exfoliative conditions.
• Embryo-fetal Toxicity: Can cause fetal harm. Advise of potential risk
to a fetus and use of effective contraception.