Insulin, Thyroid and Corticosteroid Medications

Insulin Classifications, Characteristics, and Handling

Insulin therapy requires precise timing and safe handling by the practical nurse to maintain glycemic stability. Rapid-acting insulins include lispro, aspart, and glulisine. These insulins have an onset of action of approximately 10 to 30 minutes. Because they act so quickly, the practical nurse must verify that a meal is immediately available before administering a rapid-acting insulin dose. Short-acting Regular insulin has an onset of 30 to 60 minutes and reaches its peak action approximately 2 to 4 hours after subcutaneous injection. Regular insulin is commonly used for IV insulin therapy; certain rapid-acting insulins can also be given IV when specifically ordered and permitted by facility protocol.

Intermediate and long-acting insulins provide coverage over extended periods. Neutral protamine Hagedorn (NPH) is an intermediate-acting insulin recognizable by its cloudy appearance, and it exhibits a peak action time of approximately 4 to 12 hours after administration. In contrast, glargine and detemir are long-acting insulins that provide a steady basal level with no pronounced peak. A critical rule for safety is that long-acting insulins must never be mixed in the same syringe with any other insulin. When inspecting supplies, the practical nurse checks Regular, rapid-acting, and long-acting insulins to ensure each solution is completely clear and particle-free.

Proper physical preparation and injection techniques protect the client from erratic absorption and tissue injury. Before withdrawing NPH insulin, the vial should be gently rolled between the palms rather than shaken vigorously, which avoids agitation while mixing the suspension. When mixing Regular and NPH insulins in one syringe, the practical nurse always draws the clear Regular insulin before the cloudy NPH insulin. When drawing insulin from a vial, the practical nurse uses an insulin syringe marked in units and appropriate for the insulin concentration, or an insulin pen may be used when prescribed. Subcutaneous insulin is administered at a 45-degree or 90-degree angle depending on the client's subcutaneous tissue depth.

Injection site management and temperature control are vital aspects of nursing care. The abdomen is the preferred anatomic site for rapid and consistent subcutaneous insulin absorption. Rotating injection sites within the same anatomic region helps prevent lipodystrophy and erratic drug absorption. For storage, unopened insulin vials should be stored in the refrigerator and must never be frozen. Many opened insulin vials may be kept at room temperature for up to 28 days, away from direct heat and light, though the practical nurse always checks product-specific storage instructions to ensure compliance.