Which Insulin Is Drawn Up First? The Correct Order for Mixing Insulin
The universally accepted rule is to always draw up rapid-acting or short-acting insulins before intermediate-acting (NPH) insulins when mixing them in the same syringe. This prevents contamination of the rapid-acting insulin with the longer-acting insulin, ensuring its predictable and timely action.
Understanding Insulin Types and Action
To comprehend the importance of drawing up insulin in the correct sequence, it’s crucial to understand the different types of insulin and their respective action profiles. Insulin is classified based on how quickly it starts working (onset), how long it works (duration), and when its effects are strongest (peak).
- Rapid-Acting Insulin: Begins working within 15 minutes, peaks in 1-2 hours, and lasts for 2-4 hours. Examples include lispro (Humalog), aspart (NovoLog), and glulisine (Apidra).
- Short-Acting Insulin: Starts working in 30 minutes to 1 hour, peaks in 2-3 hours, and lasts for 3-6 hours. Regular insulin (Humulin R, Novolin R) falls into this category. Note: Regular insulin can be given intravenously.
- Intermediate-Acting Insulin: Begins working in 2-4 hours, peaks in 4-12 hours, and lasts for 12-18 hours. Neutral Protamine Hagedorn (NPH) insulin (Humulin N, Novolin N) is the primary example. It is cloudy.
- Long-Acting Insulin: Starts working in several hours, has a minimal peak, and lasts for 24 hours or longer. Insulin glargine (Lantus, Basaglar) and insulin detemir (Levemir) are examples.
- Ultra-Long-Acting Insulin: Begins working in about 6 hours, no peak, and lasts for up to 36 hours. Degludec (Tresiba) is an example.
It’s important to note that long-acting and ultra-long-acting insulins are NEVER mixed with other insulins. They are intended to provide a basal level of insulin and should always be administered separately.
Why Draw Up the Rapid/Short-Acting Insulin First?
The central reason for drawing up the rapid-acting or short-acting insulin first is to prevent contamination of the rapid/short-acting insulin vial with the intermediate-acting insulin. If a small amount of NPH insulin enters the rapid/short-acting vial, it can alter the onset and duration of action of the rapid/short-acting insulin. This alteration can lead to unpredictable blood glucose control and increase the risk of hypoglycemia or hyperglycemia.
Consider this analogy: You wouldn’t want to add milk to a cup of black coffee if you wanted to drink it black, would you?
The Correct Procedure: A Step-by-Step Guide
Here is the recommended procedure for mixing rapid/short-acting and intermediate-acting (NPH) insulin:
- Wash your hands thoroughly.
- Inspect both insulin vials. Make sure the insulin appears normal (no clumps, discoloration, etc.) and is not expired.
- Roll the NPH insulin vial gently to resuspend the insulin. Do not shake it, as this can create bubbles. Clear insulins do not require mixing.
- Clean the tops of both vials with alcohol swabs.
- Draw air into the syringe equal to the NPH insulin dose and inject it into the NPH vial. Do not let the insulin touch the needle
- Remove the syringe from the NPH vial.
- Draw air into the syringe equal to the rapid/short-acting insulin dose and inject it into the rapid/short-acting vial.
- Invert the rapid/short-acting insulin vial and withdraw the rapid/short-acting insulin dose into the syringe.
- Insert the needle into the NPH vial and carefully withdraw the NPH insulin to the correct total dose.
- Administer the insulin within 15 minutes of mixing, to ensure the rapid/short-acting insulin works as designed.
Key Point: Always double-check the total dose in the syringe before injecting the insulin.
Common Mistakes to Avoid
Several common mistakes can occur when mixing insulin:
- Injecting insulin immediately after mixing. Waiting too long after mixing can affect the action of the insulin, especially the rapid-acting insulin.
- Shaking the NPH insulin. Shaking can create air bubbles, leading to inaccurate dosing.
- Contaminating the rapid/short-acting insulin vial with NPH insulin. This is the primary reason for following the correct drawing order.
- Using expired or improperly stored insulin. Always check expiration dates and store insulin according to the manufacturer’s instructions.
- Skipping meals after injection.
The Importance of Consistent Technique
Maintaining a consistent technique when mixing insulin is crucial for achieving optimal blood glucose control. Small variations in technique can lead to significant fluctuations in blood sugar levels. Always consult with your healthcare provider or diabetes educator to ensure you are using the correct technique.
Alternative Delivery Methods: Insulin Pens and Pumps
While mixing insulin in a syringe remains a common practice, insulin pens and insulin pumps offer alternative delivery methods that can simplify insulin administration.
- Insulin Pens: Pre-filled insulin pens contain a single type of insulin, eliminating the need for mixing.
- Insulin Pumps: Continuously deliver a basal rate of insulin and allow for bolus doses before meals. Insulin pumps typically use rapid-acting insulin only.
The choice of insulin delivery method depends on individual preferences, lifestyle, and blood glucose control goals.
Understanding Guidelines on Which Insulin Is Drawn Up First?
There are many guidelines about which insulin is drawn up first. While it appears to be a simple thing, consistency is key. The reason to draw up the rapid or short acting insulin first is to prevent cross-contamination between the two. If cross-contamination occurs, the action of the rapid or short acting insulins can be altered. If the person with diabetes does not know about this contamination, they could be in for some negative consequences of altered insulins. This is why it is so important to follow these guidelines.
Which Insulin Is Drawn Up First? – Summary
Ultimately, the answer to which insulin is drawn up first? is the clear insulin (rapid/short-acting) first, followed by the cloudy insulin (NPH). Following this order minimizes the risk of contaminating the rapid/short-acting insulin vial and ensures consistent blood glucose control.
FAQs: Mastering the Art of Insulin Mixing
If I accidentally inject NPH insulin into the rapid-acting insulin vial, what should I do?
Do not use the rapid-acting insulin vial. Discard the vial and obtain a new one. Using contaminated insulin can lead to unpredictable blood glucose control.
Can I mix long-acting insulin (Lantus, Levemir) with other insulins?
No, long-acting insulins should never be mixed with other insulins. They are designed to provide a basal level of insulin and should be administered separately.
What if I draw up too much insulin?
Do not inject the extra insulin back into the vial. Discard the syringe and start the process again with a new syringe. This prevents contamination of the insulin vials.
How long can I store insulin after mixing it?
It is generally recommended to administer the mixed insulin within 15 minutes. Do not store mixed insulin for later use, as its effectiveness can be reduced.
Can I pre-fill syringes with mixed insulin for later use?
While this was a more common practice in the past, it is generally not recommended due to potential stability issues. Pre-filled syringes can be used if there is a disability or vision impairment that warrants it and should be done after discussing with your diabetes care team.
What if I use an insulin pen? Do I still need to worry about this?
No, insulin pens contain only one type of insulin, so there is no need to mix. This simplifies insulin administration and eliminates the risk of contamination.
Is there a difference in technique for mixing different brands of insulin?
The basic technique remains the same regardless of the brand. However, always refer to the manufacturer’s instructions for specific guidelines.
What should I do if I’m not comfortable mixing insulin?
Consult with your healthcare provider or diabetes educator. They can provide hands-on training and answer any questions you may have.
How do I know if my insulin has gone bad?
Inspect the insulin visually. If it appears cloudy when it should be clear, or if there are clumps or discoloration, discard the insulin.
Are there any alternatives to mixing insulin?
Yes, insulin pens and insulin pumps are alternatives that eliminate the need for mixing. Discuss these options with your healthcare provider.
How does temperature affect insulin?
Insulin should be stored in the refrigerator (36°F to 46°F) until opened. Once opened, it can be stored at room temperature (up to 86°F) for up to 28 days, depending on the specific product.
How does the order I draw up insulin affect blood sugar?
The purpose of understanding which insulin is drawn up first? is to prevent any change in the onset or duration of the insulin to control blood sugar. If done incorrectly, there is a chance of increasing the potential of unexpected blood sugar changes and leading to emergency intervention.