Abstract

Background: Information on sitagliptin as a third line agent in combination with other antidiabetic agents is still lacking. This study evaluated the safety and efficacy of sitagliptin as an add-on therapyin type 2 diabetes mellitus (T2DM) patients with poorly controlled glucose control despite receiving an optimum dose ofmetforminand sulphonylurea.

Method: In a 24-week, non-randomized, open-labeled trial study, T2DM patients (n=93) who were on optimum dosage of metformin and sulphonylurea were additionally treated with 100 mg sitagliptin daily. Primary efficacy end point was assessed by investigating the changes in hemoglobin A1C (HbA1c) and a secondary efficacy end point was assessed by fasting plasma glucose (FPG). Safety was assessed by recording of hypoglycemia, change in body mass index (BMI), blood pressure, lipid profiles high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol (Tc) and triglycerides, serum aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), urea, uric acid and creatinine levels.

Result: The mean HbA1c was reduced by 0.41% (P<0.007), and overall, 18.27% of patients achieved an HbA1c goal of <7%. After 6 months. ALP was reduced by 5.23 (P=0.035) and uric acid was increased by 16.20μmol/l (P=0.048) respectively. There was no significant change in LDL, Tc, triglycerides, FPG, BMI, blood pressure, urea, AST and ALT. Hypoglycemia was observed only in a small percentage (2.65%) of patients. Although uric acid levels were slightly increased in this study, they were still within the normal range.

Conclusion: Sitagliptin is effective and safe to be used in combination with metformin and sulphonylurea therapies.

Keywords: Diabetes, dipeptidyl peptidase 4 inhibitors, sitagliptin, HbA1c