Diabetes and oral therapies : A review of oral therapies for diabetes mellitus

For decades, antihyperglycaemic agents have been used for the treatment of type 2 diabetes mellitus given their effectiveness and convenience. Metformin (MET) and sulphonylureas (SU) are time-tested antihyperglycaemic agents that have been administered for more than 50 years. These agents were followed by the introduction of other antihyperglycaemic agents such as glinides (GLN), thiazolidinediones (TZD), alpha-glucosidase inhibitors (AGI), dipeptidyl peptidase-4 inhibitors (DPP-4I), and sodium–glucose cotransporter-2 inhibitors (SGLT2I). MET is recognized as the drug of choice for monotherapy unless contraindicated or unwanted side effects occur. SU-induced hypoglycaemia is losing ground to various new agents, but the generic formulae of SU together with MET are cheap and effective. The cardiovascular hazards of several agents are a major concern to physicians and legislating bodies. In choosing antihyperglycaemic agents for dual or triple therapy, the treating physician must keep in mind the health status of the patient, medication side effects, cost, and patient preference. This review addresses the advantages and disadvantages of a range of antihyperglycaemic agents and their applications in monotherapy or combination therapy.