Non-insulin diabetes medicines: a narrative review for anaesthetists and intensivists

Diabetes mellitus is characterised by an increased blood glucose concentration. Over the past two decades, multiple new agents have emerged to help treat the condition, of which several classes of agent have been shown to reduce the risk of cardiovascular morbidity and mortality. In addition, there have been several developments in the pharmacology of non-insulin diabetes medicines, working on different aspects of gut and renal glucose absorption, hepatic metabolism, insulin sensitivity, and incretin hormone physiology. This narrative review focuses on these non-insulin diabetes medicines. We discuss the different classes, including insulin secretagogues, biguanides, alpha-glucosidase inhibitors, thiazolidinediones, sodium glucose co-transporter 2 (SGLT2) inhibitors, and the newer incretin-based therapies. Each section focuses on the mode of action but also considerations relevant to anaesthetists, surgeons, and other members of the perioperative team caring for people with diabetes mellitus receiving these agents to ensure safe care and avoidance of complications.