Question
Classify Oral antidiabetic drugs. Discuss in detail any one group. Describe briefly Human insulin. Discuss the management of Diabetic Ketoacidosis. (4+3+4+4)
Answer
Classification of oral antidiabetic drugs
| Class | Examples |
|---|---|
| Sulfonylureas | Glibenclamide, Glimepiride |
| Biguanides | Metformin |
| Thiazolidinediones | Pioglitazone |
| Alpha-glucosidase inhibitors | Acarbose |
| DPP-4 inhibitors | Sitagliptin |
| SGLT2 inhibitors | Dapagliflozin |
One group in detail — Sulfonylureas MOA: bind and close ATP-sensitive K⁺ channels on pancreatic beta cells, causing membrane depolarization, opening voltage-gated Ca²⁺ channels, and triggering insulin release — an insulin-secretagogue action requiring functioning beta cells (ineffective in type 1 diabetes). Uses: type 2 diabetes, second-line after metformin or in combination. Adverse effects: hypoglycemia (the class-defining risk, since insulin release is not glucose-dependent the way physiological secretion is), weight gain.
Human insulin Recombinant DNA-derived insulin identical in structure to endogenous human insulin (unlike older animal-derived insulins, avoiding immunogenicity concerns). Available as regular (soluble, short-acting, onset ~30 min) and NPH (isophane, intermediate-acting, onset ~1-2 hours, cloudy suspension with protamine). Largely superseded for many indications by newer insulin analogs (which better mimic physiological secretion), but remains widely used, effective, and lower-cost.
Management of diabetic ketoacidosis
- IV isotonic saline to correct dehydration, transitioning to dextrose-containing fluids once glucose approaches target range.
- IV regular insulin infusion — corrects hyperglycemia and halts ketogenesis by suppressing lipolysis; given as continuous low-dose infusion to avoid rapid osmotic shifts.
- Potassium replacement, once urine output is confirmed and serum potassium is not significantly elevated — total body potassium is depleted despite a normal/high initial serum level.
- Correction of the precipitating cause (infection, missed insulin doses), and cautious bicarbonate only in severe acidosis with hemodynamic compromise.