Pemetrexed is an anti-tumor drug, common adverse reactions include pneumonia, neutropenia, nausea, constipation, vomiting, diarrhea, etc., and serious myelosuppression. 1. Pemetrexed is mainly used for the treatment of non-small cell lung cancer, malignant pleural mesothelioma, and is contraindicated in patients with a history of severe hypersensitivity reaction to this product. 2. Common adverse reactions of pemetrexed include pneumonia, acute kidney injury, neutropenia, anemia, thrombocytopenia, weakness, fatigue, elevated blood creatinine, diarrhea, pneumonitis, nausea, constipation, diarrhea, vomiting, fatigue, fever, decreased appetite, rash, cough, dyspnea, hyperglycemia, hypoproteinemia, hyponatremia, lymphopenia, and alopecia. 3. Serious adverse reactions include bone marrow suppression, renal failure, herpetic and exfoliative skin toxicity, interstitial pneumonitis. It is recommended that patients who are unwell go to regular hospitals in time, and follow the doctor’s instructions for symptomatic treatment with medication.