The full name of ositinib is ositinib mesylate, and after oral administration, the peak plasma concentration of ositinib is reached in about 3-24 hours. Patients’ specific post-dose effects will also be evaluated based on periodic checkups. Ocitinib mesylate, an antitumor-targeted drug, is indicated for the treatment of adult patients with locally advanced or metastatic non-small cell lung cancer who have experienced disease progression on or after prior treatment with epidermal growth factor receptor tyrosine kinase inhibitors and who have been tested and confirmed to have a positive EGFRT790M mutation. Patients using the drug may have nasal bleeding, interstitial lung disease, diarrhea, rash, bone marrow suppression, liver and kidney function abnormalities; allergic to the drug is prohibited, and should consult a physician during the use of other drugs. Patients specific medication should be under the guidance of professional oncologists to avoid the occurrence of adverse effects.