SITAGLIPTIN AND METFORMIN HYDROCHLORIDE AS AN ANTIDIABETIC THERAPY: GLYCEMIC CONTROL, SIDE EFFECTS, AND ADRs IN TYPE 2 DIABETES MELLITUS

AbstractBackground: As a chronic metabolic disease, type 2 diabetes mellitus (T2DM)necessitates ongoing glucose control and treatment-related adverse drug reactions (ADRs)monitoring. When combination treatment is necessary, Sitagliptin–Metformin fixed-dosecombination (FDC) therapy is frequently utilized since it combines complimentaryprocesses.Objective: In ordinary clinical practice, assess changes in glycemic indices and defineADRs associated with Sitagliptin-Metformin FDC treatment.Methods: From January to June 2026, a prospective observational study was carried outat a hospital in Dehradun, Uttarakhand. Included were one hundred patients with type 2diabetes who had been using Sitagliptin–Metformin FDC for at least three months. Pairedt-tests were used to assess baseline and follow-up HbA1c, fasting blood glucose (FBG),and postprandial blood glucose (PPBG). WHO-UMC causality, Naranjo likelihood,Hartwig and Siegel severity, and Schumock and Thornton preventability ratings were usedto evaluate suspected adverse drug reactions.Results: All of these decreases were statistically significant (p < 0.05): FBG dropped from176.5 ± 31.8 to 132.4 ± 22.6 mg/dL, PPBG dropped from 248.3 ± 42.7 to 182.6 ± 33.4mg/dL, and mean HbA1c dropped from 8.70 ± 1.10% to 7.18 ± 0.82%). A total of 46 ADRevents were reported by 31 (31.0%) of the 100 patients. The most common adverse drugreactions were nausea (17.39%) and diarrhea (21.74%). The WHO-UMC causalityassessment classified 60.9% of ADRs as possible and 26.1% as probable/likely. TheNaranjo ADR probability scale classified 32.6% as probable and 56.5% as possible.According to the applied preventability assessment, 65.2% of ADRs were rated as mildand 58.7% as not preventable; no fatal ADRs were reported.Conclusion: In this single-center observational cohort, sitagliptin–metformin FDC therapywas associated with significant improvement in glycemic parameters and a predominantlymild ADR profile. Because the study lacked a comparator group, the findings support anassociation rather than a causal treatment effect.