Recombinant human interleukin-11 can promote the proliferation and division of megakaryocytes in bone marrow and increase the number of platelets in peripheral blood, and is commonly used clinically in patients with reduced platelet counts in peripheral blood after chemotherapy for various malignancies. It can reduce the patient’s chance of bleeding due to reduced platelet count or reduce the dependence on platelet transfusion. The usual clinical application time is 7-14 days, and the drug can be stopped after the platelet count is normalized. Common side effects of recombinant human interleukin-11 include malaise, pain, chills, nausea, and muscle pain. If an elderly patient, who usually has arrhythmias, should be especially careful when applying interleukin-11, because this drug can induce or aggravate various arrhythmias, and in severe cases, it can even induce ventricular fibrillation and lead to adverse consequences.