Calculating and Titrating Dose for Inhaled Insulin to Manage Diabetes

Diana Isaacs, PharmD, BCPS, BCACP, BC-ADM, CDCES: One of the other interesting things about inhaled insulin is that it is dosed a little bit differently than our injectable insulins. Natalie, I know you have a lot of experience using it. Can you tell us about how it’s dosed?

Natalie Bellini, DNP, FNP-BC: Sure. Inhaled insulin comes in 4-, 8-, and 12-unit cartridges. That cartridge is snapped into the inhale device, and the patient slowly inhales it when they go to use the insulin. If a patient was going to inject 4 units, they would inhale that 4-unit cartridge. If they were going to take somewhere between 5 and 8, the recommendation is that they take one 8-unit or two 4-unit cartridges; and then 9 to 12 units, the patient would inhale a 4 plus an 8 or a 12, and so on. For 13 to 16, the patient would use two 8s. There is a great graphic that comes with it that you can download and hand to the patient so that you and the patient are on the same team when you’re doing this in the beginning. Then, we do diabetes management, which is as much an art as it is a science. We might say the patient has taken and used 4 units at breakfast forever, but they are always high after breakfast. We might say use a 4, and then a couple hours later we might have them decide when and if we’re going to use another 4, and how to do that. We can make it very simple. It does not have to be complex.

Diana Isaacs, PharmD, BCPS, BCACP, BC-ADM, CDCES: Thanks for explaining that, because it does come in the 4-unit increments, which is different than other insulins, and it typically can be dosed by single unit or even in some cases by half unit, and lower if it’s a pump. Some people are thrown off by that, but the other thing is that, practice-wise, it’s more like a 2-to-1. Four units of inhaled insulin is more like 2 units of an injectable insulin. The dosing you described is usually how we start it because we do want to be conservative, so if someone is on 7 units, then it makes sense to start them at 8, since it is likely that they’re going to need more than that. Seven would be more like 14. I wouldn’t be surprised if they end up needing 12, or eventually end up need 16. We start off conservatively but expect that the dose will be higher ultimately. The advantage of starting off conservatively is that it is so easy to correct and to add more doses in for correction. You can start off with that lower dose and then an hour or 2 later if the person needs more, they can just go ahead and inhale another cartridge. You have that flexibility with the 4-, 8-, or 12-unit cartridges, just depending on the size of the dose someone’s on. There’s nothing wrong if someone just wants to have the 4 units; for example, they can just do several of the 4. It’s really fast to inhale this, and the inhaler is very small. I’m trying to emphasize that it’s like a couple [inches], it easily fits like if I had a fist like that, it would be inside there. It’s small, it goes in the pocket, it’s very discreet, it’s very easy and fast to use. There used to be a version of inhaled insulin that is now off the market. That was not so easy to use, it was the size of a box, and it was thick. I’m going to avoid saying the brand name, but it was really large. It wasn’t practical to carry around a box. For that reason, it just didn’t have much popularity. This is truly much easier to use, but it requires a mind shift because we’re so used to exact doses, like 17 units, which is more of an estimate. The truth is that diabetestruly is an art based on how we manage it.

Natalie Bellini, DNP, FNP-BC: What ends up happening is that patients tend to say, “I almost always need 12 for lunch,” and they get used to it and then they realize, “If I’m having a big lunch, I do an 8 and a 4. I usually do a 12, but if I’m having a really big lunch, I do a 12 plus a 4 knowing that I might need another 4 later.” So they do understand their blood sugar management, and it is less about the carb counting and more about whether they’re eating small-, medium-, or large-size meals, which is nice for many patients.

Diana Isaacs, PharmD, BCPS, BCACP, BC-ADM, CDCES: I agree. Another thing is that glucose monitoring helps us to be able to adjust the dose, and inhaled insulin works perfectly with continuous glucose monitoring [CGM]. People on mealtime insulin should have access to CGM, and most do. Fortunately, it’s covered by Medicare, and most insurance companies are covering it for those on mealtime insulin now. That is the perfect tool to assess how it’s working and determine if you need to increase the dose next time, or if you need to give an additional correction dose. There are a lot of people who are really savvy. This is where it’s helpful to meet with the diabetes care and education specialist. You can even learn how to interpret the arrows of the CGM. If it is rising, then you don’t need to wait as long to give another correction. Let’s give another 4 units. We don’t have to wait 4 hours. We can see that it’s rising, that partial arrow up, or you’ve got an arrow straight up and can adjust the dose based on those arrows.

Natalie Bellini, DNP, FNP-BC: We do the same thing with our patients. We send them to our diabetes care and education specialist who helps the patient use that CGM dosing and the speed of the direction of change to make some decisions with that size of the meal in the back of their head too.

Transcript edited for clarity