Purpose: The purpose of this study was to compare the safety and efficacy of DPP-4 inhibitors versus sulfonylurea as adjunctive second-line therapy in patients with type 2 diabetes mellitus, inadequately controlled with metformin mono-therapy. (PDF) Safety and efficacy of dipeptidyl peptidase-4 inhibitors vs sulfonylurea in metformin-based combination therapy for type 2 diabetes mellitus: Systematic review and meta-analysis. Available from: https://www.researchgate.net/publication/301553548_Safety_and_efficacy_of_dipeptidyl_peptidase-4_inhibitors_vs_sulfonylurea_in_metformin-based_combination_therapy_for_type_2_diabetes_mellitus_Systematic_review_and_meta-analysis#fullTextFileContent [accessed May 09 2020].