Advances in Insulin Delivery Systems - Episode 8

Inhaled Insulin in Diabetes: Adverse Effects and Lung Function Testing

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Dr Diana Isaacs and Dr Natalie Bellini review adverse effects of inhaled insulin in patients with T1D and T2D.

Diana Isaacs, PharmD, BCPS, BCACP, BC-ADM, CDCES: It’s always good to talk about, “Are there any potential downsides? Are there any potential adverse effects of taking insulin in this route of inhaling it?” I’ll just mention a few. Of course, with any insulin, there’s the risk of hypoglycemia. Insulin has a narrow therapeutic window, so that can happen with any insulin. With this, the risk is actually lower, but it still can happen. Because this is inhaled, a dry cough can occur. We’ve seen this in trials that approximately 27 percent treated with an inhaled insulin compared with 5.2 percent with comparator had experienced a cough, although it was a very small number. Only around 2.8 percent actually stopped taking it because of the cough. It’s not uncommon to cough. If you inhale something, you cough, but, usually, it’s short-lived, and it’s not something that is chronic, or staying around for a while. Other things that can occur would be throat pain, or irritation. Although, when you look the data in both type 1 and type 2 diabetes, it’s very similar between the groups that used inhaled insulin versus placebo. For example, in type 2 diabetes [T2D], coughing occurred in 3.8 percent with placebo and in 4.4 percent with inhaled insulin. In type 1 diabetes [T1D] trials, it was 1.9 percent with subcutaneous insulin compared to 5.5 percent with the inhaled insulin, so not terribly different. Of course, the trials always report minimal things that were similar between placebo groups. We didn’t see much of a difference there. Natalie, would you mind telling us a little bit about pulmonary function tests? This is an area people hear this, and they’re like, “Oh, my gosh. I need to get a pulmonologist. What’s going on?” Tell us about this and how it’s not scary.

Natalie Bellini, DNP, FNP-BC: We have primary care doctors, and so we had a pulmonary function testing machine in our practice, but the company that makes the inhaled insulin helps to do them as well. You have many resources to get this done, but you need to do a pulmonary function test. Sometimes we miss things, and we need to know if this patient has good pulmonary function before we give them a drug that’s going to be absorbed through that means. It needs to be done beforehand, starting at 6 months, and then annually. In the beginning, we thought, “Oh, this is going to be a lot of work.” No, it’s not. Patients love their inhaled insulin, and we just say, “This is part of it. Here we go.” It’s like having to do a C-peptide, if you have a patient who needs to have that done to get an insulin pump, or any other testing that has to happen.

Diana Isaacs, PharmD, BCPS, BCACP, BC-ADM, CDCES: A potential adverse effect could be a decrease in FEV1 [forced expiratory volume in 1 second], which is a pulmonary test. That’s why it should be monitored. It’s natural as a person ages that FEV1 will decline. That is a natural progression of what can happen. In clinical trials, FEV1 of greater than a 15-percent reduction occurred in six percent of the inhaled insulin versus three percent of comparator. It’s very similar. However, we still monitor it. Like you said, what if someone had preexisting asthma, or COPD, and we didn’t know about it. That’s why we do it at baseline. Now, it’s not scary, because the test is simple, and you can do it in your office. Anyone can do it. It involves a small little device that you can get for free from the company that makes inhaled insulin. Otherwise, they’re very low-cost and a person blows into it 3 times. You replace the tube that goes on it, so you keep it sanitary and that measures their FEV1. It takes like 2 minutes to do it, and it’s something that we have available. Our health care professionals can administer it. It’s just a very small thing that does not add much onto the visit at all. You don’t need to refer out to a pulmonologist, or anything like that to get them started. Once you see how simple it is, it is easy to do and incorporate into practice.

Natalie Bellini, DNP, FNP-BC: I absolutely agree. It takes us minutes.… My medical associate does them, brings the results, then I sign off on them and we’re good to go.

Transcript edited for clarity