Final answer:
The most common parenteral route for injecting insulin is the subcutaneous (SubQ) route, which is favored for its slower, more controlled insulin release. Insulin injections are crucial for regulating blood glucose levels, particularly after high-glucose meals for people with diabetes.
Step-by-step explanation:
When injecting insulin, the parenteral route that is most commonly used is the subcutaneous (SubQ) route. This method involves injecting insulin into the fatty tissue just beneath the skin. This route is preferred because it allows for a slower, more controlled release of insulin, which helps to decrease blood glucose levels after consuming a meal, particularly a large or high-glucose meal.
For treatment of systemic infections, where oral administration is not effective due to poor absorption in the GI tract, or when higher plasma levels are required, parenteral routes such as intravenous or intramuscular injections are typically administered in health-care settings. Insulin injections specifically are crucial for the transport and storage of glucose as they help to regulate blood glucose levels, which is essential for people with diabetes.