Formulation and Specifications: Tablets: 250 mg
Indications: Locally advanced or metastatic non-small cell lung cancer (NSCLC) with sensitive mutations in the epidermal growth factor receptor (EGFR) gene.
Key points for rational drug use:
1. The presence of EGFR-sensitive mutations detected by EGFR gene testing methods approved by the National Drug Administration (NMPA) must be clearly established prior to drug administration.
2. Both tumor tissue and blood can be used for EGFR gene mutation detection, but tissue detection is preferred. This criterion also applies to other small molecule tyrosine kinase inhibitors.
3. When drug toxicity is intolerable during treatment, substitution between drugs of the same generation is allowed, but not between drugs of the same generation if the disease progresses.
4. Patients whose imaging shows slow progression but no deterioration of clinical symptoms during treatment can continue to use the original drug; patients who show oligoprogression or CNS progression can continue to use the original drug plus local treatment; for patients with extensive progression, it is recommended to switch to other treatment regimens. This criterion also applies to other small molecule tyrosine kinase inhibitors.
5. Common skin mucosal reactions and diarrhea must be noted during drug administration; special attention should be paid to the occurrence of interstitial pneumonia, hepatotoxicity, and ocular symptoms.
6. Drug interaction dose adjustment: (1) CYP3A4 strong inducer: If no serious adverse drug reactions occur, the daily dose of gefitinib may be increased to 500 mg, and gefitinib 250 mg dosing is restarted 7 days after discontinuation of strong CYP3A4 inducer dosing. (2) CYP3A4 inhibitors: Strong CYP3A4 inhibitors (such as ketoconazole and itraconazole) can reduce gefitinib metabolism and increase its plasma concentration. Adverse effects should be monitored when gefitinib is combined with potent CYP3A4 inhibitors.
*7. In certain oncologic emergencies such as coma with brain metastases or respiratory failure, well-informed patients with nonsmoking lung adenocarcinoma may be considered for dosing as soon as possible in the absence of an unknown driver gene. Once in remission, additional tissue or blood testing for EGFR mutations must be performed. (This criterion also applies to other EGFR tyrosine kinase inhibitors)