Ocitinib Mesylate Tablets is a third generation EGFR tyrosine kinase inhibitor for patients with advanced lung cancer with EGFRT790m mutation who have progressed after previous EGFR-TKI therapy. Genetic testing is recommended to identify the presence of the T790m target that the drug acts on before administration. The recommended dose is 80 mg orally daily. Adverse effects of oxitinib include rash, diarrhea, stomatitis, and hematologic toxicity such as leukopenia and thrombocytopenia. Particular attention should be paid to monitoring platelets, and there may be some other adverse reactions such as impairment of liver function and kidney function. The drug should also be monitored during administration, and the dosage should be reduced or stopped if necessary, and symptomatic treatment should be provided in a timely manner.