When mixing NPH and regular insulin, what is the first type of insulin to draw?

When mixing NPH (intermediate-acting insulin) and regular insulin (short-acting insulin), the correct procedure dictates that regular insulin should be drawn first. This practice is important to ensure proper dosing and to minimize the risk of contamination.

Regular insulin has a different formulation compared to NPH, which contains additives that can cause it to be cloudy. By drawing the clear regular insulin first, the syringe remains free from any potential contaminating particles that might affect the absorption and action of the short-acting insulin. If NPH were drawn first, there is a risk that small amounts of the cloudy insulin could mix with the regular insulin, potentially altering its effectiveness when administered.

Following this procedure helps maintain the integrity of the insulin types, ensuring each type performs as intended when administered, resulting in more stable blood glucose management for patients.