Chapter 33: Antidiabetic Drugs – Insulins & Oral Agents

The text distinguishes between Type 1 diabetes—an autoimmune disorder resulting in absolute insulin deficiency that necessitates replacement therapy—and the more common Type 2 diabetes, which is primarily characterized by insulin resistance and a relative insulin shortage. Diagnosis relies on established criteria such as elevated fasting plasma glucose levels (≥7 mmol/L) or a high Hemoglobin A1C (HbA1C) reading, the latter serving as a key measure of glycemic control over several months. Treatment strategies prioritize nonpharmacological interventions like exercise and diet, followed by drug therapies aimed at preventing severe complications such as Diabetic Ketoacidosis (DKA) or Hyperosmolar Hyperglycemic State (HHS). Pharmacological options include exogenous insulins, classified by their duration of action (rapid, short, intermediate, and long-acting), and administered using tailored regimens like basal–bolus therapy to closely mimic natural pancreatic function. For Type 2 management, a diverse set of oral and injectable antihyperglycemics are used, including the first-line biguanide metformin (which decreases hepatic glucose production), sulfonylureas and glinides (insulin secretagogues), insulin-sensitizing thiazolidinediones, and newer classes like DPP-4 inhibitors and SGLT2 inhibitors. Crucial topics covered also include recognizing and treating emergencies like hypoglycemia with fast-acting glucose sources or injectable glucagon, and implementing essential nursing care focusing on accurate drug administration, proper insulin handling and injection site rotation, continuous glucose monitoring, and patient education regarding diet, foot care, and special considerations for vulnerable populations, such as Indigenous Canadians who face increased risk and complications.