Physician order says "Infuse Regular Insulin at 8 units/hr". You're supplied with an IV bag of the prescribed medication that reads "125 units per 250 ml". What will you set the infusion pump at (mL/hr) so your patient will receive 8 units/hr?

Rationale:

A. Insulin is a protein-based hormone. Freezing causes crystal formation and denaturation of protein structure, which destroys the insulin's ability to lower blood glucose. Using frozen insulin can lead to hyperglycemia due to ineffective doses. Therefore, freezing is contraindicated.

B. Freezing insulin, whether opened or unopened, renders it inactive. Proper storage is essential to maintain potency; storing in a freezer is a common error that can result in ineffective therapy and poor glycemic control.

C. Refrigeration (2–8°C / 36–46°F) preserves insulin stability and potency until the expiration date. Most insulin formulations remain effective for the full shelf life when stored this way. Keeping unopened insulin in the fridge also reduces the risk of accidental temperature fluctuations that can degrade the medication.

D. Once insulin is opened, most vials or pens can be kept at room temperature (up to 30°C / 86°F) for a limited period (usually 28 days for many types, longer for some formulations) without loss of efficacy. Room temperature storage: Reduces injection discomfort (cold insulin can cause burning), maintains potency if within manufacturer-specified duration and must still avoid extremes of heat or freezing

Rationale:
A. This is correct understanding. Glyburide, a sulfonylurea, can interact with alcohol to cause severe hypoglycemia or a disulfiram-like reaction. Complete avoidance of alcohol is recommended, so this statement shows proper comprehension.

B. Alcohol can enhance the hypoglycemic effects of glyburide, leading to symptoms such as dizziness, lightheadedness, or fainting. The client recognizing this risk demonstrates understanding of medication-alcohol interactions.

C. Alcohol can potentiate the blood-glucose-lowering effects of glyburide by inhibiting gluconeogenesis, increasing the risk of hypoglycemia. This statement shows the client understands the potential danger.

D. Even small amounts of alcohol can precipitate hypoglycemia in clients taking glyburide, particularly if alcohol is consumed without food. This statement indicates a misunderstanding of the risks, so the nurse should provide further teaching to emphasize complete avoidance of alcohol while on sulfonylureas.