The difference between Selegiline Phosphate Tablets and Alogliptin Benzoate Tablets lies in the half-life of the drug, the dosage used and other aspects. Sitagliptin Phosphate Tablets and Alogliptin Benzoate Tablets both belong to DDP-4 inhibitors and are mainly used in the treatment of type 2 diabetes mellitus. Both can stimulate insulin secretion and inhibit glucagon secretion, so as to achieve the purpose of lowering blood sugar. 1. Different half-life: the half-life of selegiline phosphate tablets is 12.4 hours, and the half-life of alogliptin benzoate tablets is 21 hours. Both are administered once a day. 2. Different dosages: Selegiline phosphate tablets are normally recommended at a dose of 100mg once a day, and there is no need to adjust the dosage when the endogenous creatinine clearance is ≥45ml/min. Alogliptin benzoate tablets recommended dose of 25 mg once daily, endogenous creatinine clearance ≥ 60 ml/min, do not need to adjust the dose of the drug. Selegiline phosphate tablets should be cautioned not to be used in patients with type 1 diabetes mellitus or for the treatment of ketoacidosis. Selegiline phosphate tablets are contraindicated in people who are allergic to them. Selegiline phosphate tablets may cause nausea, vomiting, abdominal pain and other adverse reactions. Alogliptin benzoate tablets should be used with caution in patients with pancreatitis, and the use of alogliptin benzoate tablets is prohibited in the presence of angioneurotic edema. The use of alogliptin benzoate tablets may cause pancreatitis, nasopharyngitis, headache, allergy and other adverse reactions. Patients who need to use Sitagliptin Phosphate Tablets or Alogliptin Benzoate Tablets for treatment are required to use them under the guidance of a professional doctor.