Which type of insulin can be given intravenously?

NORCET 5 Prelims - Sept 2023 (Shift-1)

Pharmacology

Easy

Appeared in: NORCET 5 Prelims - Sept 2023 (Shift-1)

Explanation

Regular insulin is a short-acting, soluble, crystalline zinc insulin that is formulated as a clear solution.
Because it is a true solution without any added modifying proteins or particles, it is safe for intravenous administration.
IV administration is necessary in clinical emergencies like diabetic ketoacidosis (DKA) and during perioperative glucose management to achieve rapid control of blood sugar.
Its effects begin within 30 minutes of subcutaneous injection, but are almost immediate when given intravenously.

Option A: NPH (Neutral Protamine Hagedorn) insulin is an intermediate-acting insulin that appears cloudy because it is a suspension containing protamine. Administering a suspension intravenously can cause embolism.
Option C: Humulin is a brand name for various insulin products, not a specific type. While Humulin R is Regular insulin and can be given IV, Humulin N is NPH insulin and cannot. The option 'Humulin insulin' is too general and therefore incorrect.
Option D: Lente insulin, similar to NPH, is an intermediate-acting insulin suspension. It is cloudy and not suitable for intravenous administration due to the risk of particulate matter entering the bloodstream.

Visual 1: Diagram - A side-by-side comparison of a clear vial of Regular insulin and a cloudy vial of NPH insulin. The caption should state: 'Only clear, short-acting Regular insulin can be given IV. Cloudy insulins are suspensions and for subcutaneous use only.'
Visual 2: Flowchart - A decision tree for insulin administration, showing the question 'Is the route IV?' leading directly to 'Use Regular Insulin ONLY', while the 'Subcutaneous' route branches out to various insulin types (Rapid, Short, Intermediate, Long-acting).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Routes of Administration for Different Insulin Types as background academic context rather than a clinical decision trigger.
IV Regular insulin is a cornerstone of treatment for hyperglycemic crises such as Diabetic Ketoacidosis (DKA) and Hyperosmolar Hyperglycemic State (HHS), where rapid and precise control of blood glucose is life-saving.
A critical nursing safety check is to always verify the insulin type and route. Administering a cloudy insulin (like NPH) intravenously is a serious medication error that can lead to pulmonary embolism and death.
What if? If a nurse receives an order for 'IV NPH insulin', the correct action is to immediately question the order with the prescribing physician and pharmacist, clarify that only Regular insulin can be given IV, and prevent a potentially fatal error.

How to Approach the Question

First, identify the key terms in the question: 'insulin' and 'intravenously' (IV).
The question asks for a specific type of insulin suitable for a specific, high-risk route of administration.
Recall the fundamental properties of different insulins. The main distinction for IV use is whether the insulin is a solution (clear) or a suspension (cloudy).
Remember that suspensions contain particles that are unsafe for direct injection into the bloodstream.
Evaluate the options: NPH and Lente are known to be cloudy suspensions. 'Humulin' is a brand name, not a specific type. 'Regular insulin' is known as a clear, short-acting solution.
Conclude that only Regular insulin meets the criteria for safe intravenous administration.

Concept Tested & Keywords

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