Jay H. Shubrook, DO: Hello. This is Jay Shubrook, DO. I am a professor in the primary care department at Touro University, and I am happy today to be interviewing Lucia Novak, an adult nurse practitioner who is board certified in advanced diabetes management. She is director of the Riverside Diabetes Center in Riverdale, Maryland. Today we will be talking about basal insulin—how to choose between insulin products and best practices in choosing insulins.
You have a very busy diabetes practice, Lucia. There are now many basal insulins to choose from. How do you pick?
Lucia M. Novak, MSN, ANP-BC, BC-ADM: That is a very good question, and it is one that I am asked a lot by primary care providers, especially because so many insulins have come out in the past few years. It's sad to say that what drives which insulin we choose is what is most affordable for the patient. The bottom line is, which insulin will be covered by the patient's insurance? The newer insulins are very expensive. Some of our patients have very limited medication plans and very high deductibles, so without insurance coverage, the choice is limited.
If I eliminate that from the equation and the different insulins are equally available and accessible, which insulin to choose depends on other factors. There are some nuances that we must consider—some things about the patient that must be brought into the conversation to help us decide which insulin is the most appropriate.
Dr Shubrook: Can you give us some examples?
Ms Novak: We ask, what exactly are we trying to address? Does the patient have a very strong dawn phenomenon, in which blood sugars are elevated in the morning and then as the day progresses they tend to improve to the point that the patient may actually have low-normal blood sugars before going to bed? Should I choose an insulin that covers 24 hours but which could cause a problem with hypoglycemia when the patient's blood sugar is within an appropriate range? Another nuance is how often the patient is able to administer insulin. How successful will the patient be if there is more than one daily injection?
Some of the basal insulins that are available, including the older products, do not have a profile that is 24 hours in duration. They also are only available in a U100 concentration. That may require twice-daily dosing of the basal insulin to get full 24-hour coverage, as well as to eliminate some of the large doses that are delivered if more than 50 units are injected at once.
The newer basal insulin—degludec U200 and the insulin glargine U300—are concentrated so that they deliver the same dose of insulin in a lower volume. The U300 can be administered in one third of the volume than what the patient is currently injecting, and the U200 is half the volume. That makes a difference to our patients.
If a patient is not successful with more than once-daily insulin dosing, especially with basal insulin, that is where some of the longer-acting basal insulins come into play because they last at least 24 hours. The U300 glargine lasts longer than 24 hours, and degludec (either the U100 or the U200 concentration) has a duration close to 40 hours. It depends on what is going on with the patient, how successful the patient is with his or her current insulin, and our target for controlling the patient's diabetes.
Is There Still a Place for NPH?
Dr Shubrook: This sounds complicated. When I think of basal insulin, I think of five different insulins: human NPH, insulin glargine, insulin detemir, and the longer-acting basal insulins—insulin glargine U300 and insulin degludec. Because cost is an issue, when would you use NPH?
Ms Novak: NPH is still a very good insulin, and I do use it at times. For instance, I might use it with a patient who has a really strong dawn phenomenon but has blood sugars that are in relatively good control the rest of the day. I actually had a patient who was doing well, with an A1c of about 7.5%. Her morning blood sugars were consistently above 200 mg/dL but she was in the 80-90 mg/dL range the rest of the day. She was on repaglinide, a glinide medication that she took before lunch and dinner only, and that was all she needed. When I tried her on U100 glargine or detemir, which were available at the time I was treating her, she would end up with hypoglycemia because the glargine was lasting far too long during the latter part of the day. The detemir was not giving her enough of a peak to address the dawn phenomenon. The insulin was lingering too long and causing hypoglycemia around midday. However, I used NPH insulin for her at bedtime, trying to take advantage of its peak effect, which occurs 6-8 hours after taking it. This timed well with when the dawn phenomenon was kicking in. NPH tends to wear off around the time that she did not need it as much.
Another circumstance in which I use NPH is for patients who are on prednisone. I consider it my "steroid insulin," and the time that patients take their prednisone is also when their NPH is dosed. When you look at the pattern of steroid-induced hyperglycemia, the insulin that best matches and addresses this pattern is NPH insulin. I have patients take their NPH at the same time that they take their dose of prednisone in the morning, and we have much better blood glucose control during the day without the risk for hypoglycemia overnight, when the prednisone is wearing off.
The other time that I would use NPH in preference to another insulin is in pregnant women. Most insulin is a category B drug in pregnancy. (Glargine U100 and U300, degludec U100 and U200, and glulisine are all category C.) NPH can be very effective in some of our pregnant women, especially those with gestational diabetes, to manage their typical blood glucose elevations. We can see some really good effects with the NPH in that population.
It Helps to Have Choices
Dr Shubrook: It sounds like you have really been able to utilize the spectrum of basal insulins to fine-tune your treatment. You have NPH, which you use at nighttime, or maybe twice a day if cost is an issue. Glargine or detemir are intermediate, and for patients who need an extended period of time or if they need higher doses of insulin, you can use the concentrated insulin. This has helped your practice, correct?
Ms Novak: It has. It helps to have choices. Choices can be overwhelming when you are not sure what to do, but there is an insulin for every patient, and there is a patient for every insulin. I do not believe that any of these insulins truly replaces the other. You just need to take the onset of action, peak, and duration of the insulin into account. Does it have a peak? What is going on with the patient? To know that, you need the patient to be engaged, and you need to know what those blood sugar patterns are. Fortunately, we also have the ability to do continuous glucose monitoring in the professional setting, which allows us to have patients wear those devices for 3 days or a week so that we can identify those patterns. We use that information to target which insulin we think would be most appropriate for that patient. We have a lot of tools available to help us decide. Much of the knowledge about choosing an insulin is experience-based—both the patient's as well as the clinician's.
Dr Shubrook: That is fabulous. We appreciate you taking time today to talk with us about how you use basal insulin, and keep doing great work in your practice.
Ms Novak: Thank you.
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Cite this: How to Choose a Basal Insulin - Medscape - Dec 12, 2016.