Hypoglycaemic Drugs

Hyperglycaemia is a common problem in hospitalized patients, more so in the critically ill population. Diabetes mellitus (DM) is a chronic, progressive, complex metabolic disorder, featured by hyperglycaemia, impaired insulin secretion, resistance to tissue actions of insulin, or its combinations. Hypoglycaemic drugs are agents that decrease the blood glucose levels and are used to treat diabetes mellitus. These anti-hyperglycaemia agents can be administered either systemically or orally. These not only provide adequate glycemic control but also prevent long-term and short-term (micro-vascular and macro-vascular) complications of DM. Oral hypoglycemics have a limited role in the management of hyperglycaemia in hospitalized, critically ill patients, in view of slow onset of action, low potency, variable gastrointestinal absorption, and a multitude of adverse effects. Neurocritical care patients also are prone to hyperglycaemia due to preexisting or new-onset diabetes mellitus and stress-induced hyperglycaemia, which if not controlled, can result in deleterious consequences and secondary brain injury. It is imperative to maintain optimal glycemic levels, in the range of 140–180 mg/dL (7.8–10 mmol/L) in all patients, and sometimes with stricter control in certain critically ill patients (110–140 mg/dL), for better patient outcome. Insulin is the cornerstone of hyperglycaemia management in critically ill patients. This chapter gives a detailed account of the pharmacology of oral and systemic hypoglycaemic agents, including insulin used in clinical practice.