Mixing NPH and Regular insulin is a common practice for some individuals managing diabetes. This technique allows for a combination of immediate and sustained blood sugar control from a single injection, potentially simplifying the daily routine. Understanding the precise method for mixing these insulins is important for effective diabetes management. This information is for educational purposes; always consult a healthcare professional for changes to insulin therapy.
Understanding Insulin Types and the Rationale for Mixing
Insulin, a hormone produced by the pancreas, helps regulate blood sugar levels. For individuals with diabetes, external insulin administration is necessary when the body doesn’t produce enough or use it effectively. Different insulin types are categorized by their action profiles: how quickly they start working, when they reach their peak effect, and how long their effects last.
Regular insulin, a short-acting type, typically begins to lower blood sugar within 30 minutes to 1 hour, peaks in 2 to 4 hours, and lasts up to 6 to 8 hours. NPH (Neutral Protamine Hagedorn) insulin, an intermediate-acting type, has an onset of 1 to 3 hours, peaks in 6 to 8 hours, and lasts 12 to 24 hours.
The rationale for mixing Regular and NPH insulin stems from their complementary action profiles. Regular insulin provides a rapid reduction in blood sugar, addressing post-meal glucose spikes. NPH insulin offers sustained blood sugar control over several hours, providing basal insulin coverage between meals and overnight. Combining these two types in a single syringe allows for both immediate and prolonged glucose management with fewer daily injections, which can improve convenience.
Essential Supplies and Preparation
Before mixing insulin, gather all necessary supplies. You will need two vials: Regular (clear) and NPH (cloudy) insulin. An appropriate U-100 insulin syringe and alcohol wipes for cleaning vial tops and the injection site are also required.
Wash hands thoroughly to minimize contamination risk. Inspect each insulin vial carefully. Regular insulin should appear clear and colorless, without particles or discoloration. NPH insulin should appear uniformly cloudy; if settled, gently roll the vial between your palms until evenly mixed. Avoid vigorous shaking, which creates air bubbles and can affect effectiveness. Always check expiration dates and discard any insulin that is expired, discolored, clumpy, or shows signs of damage or contamination.
The Step-by-Step Mixing Procedure
Mixing NPH and Regular insulin requires a precise sequence to maintain the integrity of both insulin types and ensure accurate dosing. The fundamental principle is “clear before cloudy”: Regular insulin is drawn into the syringe before NPH insulin. This order prevents contamination of the Regular insulin vial with NPH’s protamine, which could alter its rapid-acting properties.
First, gently roll the NPH insulin vial to ensure the suspension is uniformly mixed. Clean the rubber tops of both NPH and Regular insulin vials thoroughly with separate alcohol wipes.
Draw air into the syringe equal to your NPH dose. Insert the needle into the NPH vial and inject this air, taking care not to touch the liquid insulin. Remove the syringe.
Next, draw air into the syringe equal to your Regular insulin dose. Insert the needle into the Regular insulin vial and inject this air. Without removing the needle, invert the Regular insulin vial and carefully draw the prescribed dose. Be precise; if you overdraw, discard the syringe and start over with a new one.
Once Regular insulin is drawn, carefully insert the needle into the NPH insulin vial. Invert the NPH vial and draw the prescribed NPH dose into the same syringe, being careful not to push any clear insulin back into the NPH vial. The total volume in the syringe should now be the combined dose. After drawing NPH, remove the syringe and check for air bubbles. If present, gently tap the syringe to move them to the top and carefully push the plunger to expel only the air. Inject the mixed insulin immediately after preparation.
Important Safety Practices and What to Avoid
Adhering to strict safety practices is important when mixing NPH and Regular insulin to ensure effective blood sugar control and prevent complications. The rule of “clear before cloudy” (Regular before NPH) is a safety measure; reversing this order can contaminate the Regular insulin vial, altering its rapid action and leading to inconsistent blood sugar levels. If NPH is accidentally drawn first, discard the entire dose and restart with a new syringe.
Never reuse syringes; each injection requires a new, sterile syringe to prevent infection or tissue damage. Do not mix NPH or Regular insulin with other insulin types, particularly long-acting basal insulins like glargine or detemir, as this can lead to unpredictable absorption and blood sugar fluctuations. Never adjust insulin doses or change the mixing regimen without explicit healthcare provider instructions, as incorrect dosing can result in severe hypoglycemia or hyperglycemia.
Proper insulin storage is also a safety consideration. Unopened insulin vials should be stored in the refrigerator until their expiration date. Once opened, vials can typically be stored at room temperature (below 86°F or 30°C) for up to 28 days; consult manufacturer instructions. Never freeze insulin or expose it to direct sunlight or extreme temperatures, as this reduces potency. If mixed insulin appears cloudy, discolored, or contains particles or clumps, discard it.