The past decade has seen the emergence of several new classes of drugs for the treatment of type 2 diabetes mellitus (T2DM). Despite the increasing use of these agents, metformin and sulfonylureas remain the most commonly prescribed glucose-lowering drugs in people with T2DM. This reflects the National Institute for Health and Care Excellence (NICE) guideline from 2015 and the Scottish Intercollegiate Guidelines Network (SIGN) guideline from 2010, which recommended metformin as first-line treatment and sulfonylureas as the ‘usual’ second-line treatment for patients with T2DM. SIGN has recently provided an updated guideline on the pharmacological management of glycaemic control in people with T2DM. For the first time in UK guidelines, this recommends that in individuals with diabetes and cardiovascular disease, sodium-glucose co-transporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists with proven cardiovascular benefit (currently empagliflozin, canagliflozin and liraglutide) should be considered. It is anticipated that implementation of these new guidelines will lead to increased prescribing of these drugs in people with diabetes and cardiac disease, with reductions in prescribing of dipeptidyl peptidase-4 (DPP-4) inhibitors and other drugs in the GLP-1 receptor agonist class, where cardiovascular benefits have not been clearly demonstrated.