Onglyza contains saxagliptin. Onglyza is indicated in adult patients aged 18 years and older with type 2 diabetes mellitus to improve glycaemic control. Its side effects include upper respiratory tract infection, urinary tract infection, headache, gastroenteritis, dizziness, and fatigue. Fatigue or tiredness is a very common side effect of Onglyza. Your concern is about risk of heart failure in patients using Onglyza But FDA has issued warnings on use of Onglyza in patients with known risk factors for hospitalization for heart failure, such as a history of heart failure or moderate to severe renal impairment. And you are not in these categories. So there is no need to worry. Symptoms of heart failure are • Shortness of breath when you exert yourself or when you lie down • Fatigue and weakness • Swelling (edema) in your legs, ankles and feet • Rapid or irregular heartbeat • Reduced ability to exercise • Persistent cough • Increased need to urinate at night • Swelling of your abdomen (ascites) • Sudden weight gain due to fluid retention • Lack of appetite and nausea Only on the basis of fatigue or tiredness, it cannot be said that you are suffering from heart failure. Patients with diabetes may have fatigue due to a. Anemia b. Wasting due to uncontrolled diabetes c. Side effect of drugs d. Electrolyte imbalance e. Diabetic nephropathy f. Diabetic neuropathy Advice 1. Continue Onglyza as suggested 2. If you have also above symptoms of heart failure then immediately contact your doctor 3. Investigations a. Serum creatinine b. Blood sugar (F & PP) c. Lipid profile d. Hb% e. Serum Na & K Consult your doctor for further follow up management. Thanks