Insulin Dose Optimization and Glycemic Control

Dhiren Patel, PharmD, and Serge Jabbour, MD, provide insight regarding how they make decisions regarding insulin dose optimization and discuss potential problems that can arise.

Dhiren Patel, PharmD: With poor glycemic control comes a lot of different complications that you need to worry about. Ones that we know we have specific data and very good trials for are microvascular complications. And so, I always tell patients and other providers and folks that I interact with that less than 6.5% or less than 7% wasn’t a number that was picked out of a hat. The reason why we have those numbers in our guidelines is because we know that if the patient is maintained at those numbers, their chances of having microvascular complications such as retinopathy, neuropathy, or nephropathy are going to be much less than if a patient was sitting at a higher A1C level. And so, those are some of the long-term complications that a patient would experience with uncontrolled A1C. The other thing is that macrovascular complications can also be an issue with poor glycemic control. So, it’s not just the microvascular complications. The shift is now going to macrovascular complications as well.

Serge Jabbour, MD: When we start insulin in type 2 diabetes, the key is to decide initially what patients can handle. I try to explain to patients that based on normal physiology, we need to give them 1 injection of the basal insulin and then 1 injection of a mealtime insulin every time they eat. But that will end up being 4 injections a day. Some patients cannot handle this. If patients tell me, “There’s no way I’m going to do more than 1 shot,” there’s no point forcing patients to do something when we know they will not be compliant. Then, I would pick 1 injection of basal insulin, get them to my diabetes educator, and over time teach these patients—educate them—that they will end up needing more insulin injections.

I think most of the time with patients’ insulin injections, they have that fear of insulin, fear of injections. Once they get on it and they use the pen and the small needle, they see it’s not as bad as they thought. Over time, they can accept more injections. Many times, I start with 1 injection of basal insulin, and typically we do 10 units at bedtime. We titrate based on the fasting sugars in the morning, and we teach patients to look at their fasting sugars every 3 days. The goal is 80 mg/dL to 130 mg/dL. If you’re running above 130 mg/dL by 3 days, you go up by 2 units on the basal insulin. So, every 3 days, patients can adjust the insulin dose. And I tell them, “If you’re not comfortable, fax me your sugars in 3 days, 6 days, or a week, and I will call you back and make the adjustments.”

When I see patients who are in a catabolic state—meaning they are losing weight in a phase of high A1C, usually more than 9%—these patients have a complete lack of insulin, which means they need to be on basal and mealtime insulin at the same time. If patients cannot handle 4 injections a day, we have the option of using the premixed insulin as 2 injections a day. It’s not the best, but it’s a good offer to start with until they see my diabetes educator.

For other patients with an A1C level that is not at goal but not in a metabolic state, I add 1 injection of basal insulin because that’s easy. It’s 1 shot a day, they take it in the evening at bedtime, and then over time we make a decision if we need to add mealtime insulin. The question is, when do we know that they need another type of insulin, usually mealtime? If you add the injection at night of the basal insulin, and let’s say a few weeks later the fasting sugars are between 80 mg/dL to 130 mg/dL but the A1C level is still high or they still have high sugar levels during the day, then we know there’s an issue with the postprandials. That means we need to add a mealtime insulin. But let’s say after a few weeks the fasting sugars are great, sugars during the day look all great, and the A1C level comes down to 6.5%. Then just 1 injection of basal did all the work and that’s all that was needed.

Dhiren Patel, PharmD: I think the pharmacist has a very important role when it comes to proper glycemic management. But when you’re talking more specifically about insulin management, there’s a lot of upfront counseling and education that is done by pharmacists—that should be done by pharmacists–in bringing down some of these barriers about self-management skills of how to treat a low blood sugar if it were to happen, injection technique, and storage. But the additional factors that go beyond that are not just initiating the first dialogue and conversation, but what also happens after that. In many prescriptions that are written, you’ll see that of insulin is initiated as 10 units at bedtime, but then they’re on their third fill and they’re still getting 10 units at bedtime. So, because they haven’t gone back to see their provider, that titration of insulin doesn’t happen.

As the pharmacists who have more touch points and more dialogue with that patient, that is something where you could intervene in saying, “How has it been working out since you started that insulin now? What are your fasting blood sugars looking like?” Care coordinate that back to the provider or even make suggestions on how to titrate that. Many providers will empower their patients with self-titration saying, “Please increase your insulin by 2 units every 2 days, or every 3 days, until you get to a fasting plasma glucose goal of X number.” As a pharmacist, you can help them achieve that titration protocol and make sure that they actually use that therapeutic dose.