The generic name of Berritto is rivaroxaban. The course of anticoagulation therapy with rivaroxaban for pulmonary embolism needs to be at least three months, or longer if there are risk factors for embolism. Once the diagnosis of acute pulmonary embolism is confirmed, treatment with a drug such as rivaroxaban is required immediately if there are no absolute contraindications to anticoagulation. The standard course of anticoagulation therapy is at least 3 months. In some cases of pulmonary embolism, thrombotic risk factors persist after 3 months of anticoagulation therapy, and in order to minimize their recurrence rate, extended-phase anticoagulation therapy needs to be continued. The exact duration of extended anticoagulation therapy varies widely and needs to be determined by the clinician taking into account multiple factors such as disease recurrence, residual thrombus, D-dimer levels, etc., in order to find the optimal balance of risk and benefit between bleeding and recurrence. If the risk of recurrence significantly exceeds the risk of bleeding, prolonged anticoagulation or even lifelong anticoagulation is required. In the event of bleeding, thrombocytopenia, jaundice, angioedema, cerebral hemorrhage, or other serious adverse events during treatment, the drug must be immediately discontinued and the patient must be seen. The drug is contraindicated in cases of drug allergy, the presence of markedly active bleeding, coagulation abnormalities, severe hepatic injury, extended anticoagulation therapy with other anticoagulants such as heparin, pregnancy and lactation. Rivaroxaban needs to be administered under the supervision of a clinician.