Building Competency in Diabetes Education THE ESSENTIALS

BASAL-BOLUS INSULIN THERAPY | 12-31

During the following discussion regarding the selection of the basal and bolus insulins the insulins will be referred to by their active ingredient. The studies referenced to support the clinical use of the insulin were done with the original reference biologic unless otherwise noted. It will be left to the judgement of the reader as to the interchangeability with the biosimilar medications and their use in their clinical practice.

Bolus Insulin Selection Concentrated bolus insulins will not be discussed in this chapter. For more information on these insulins, please see Chapter 6: Pharmacological Therapies.

Regular human insulin or rapid-acting insulin analogues • Regular insulin in solution aggregates, forming hexamers. Aggregates of the insulin molecule must dissociate after injection, delaying insulin action. • Insulin analogues, which have been available in Canada since 1997, demonstrate absorption properties that more closely mimic normal postprandial insulin availability. Insulin lispro was introduced first, followed by insulin aspart, then glulisine (2009) and faster-acting insulin aspart (2017). o Analogues dissociate from hexamers to monomers more quickly, resulting in faster peak action and less variability of analogues compared to regular insulin. o Faster-acting insulin aspart is insulin aspart with the addition of L-arginine as a stabilizing agent and niacinamide to accelerate initial absorption (52). Educators and individuals with diabetes should remember that some principles used with short-acting insulin still need to be considered with rapid-acting analogue therapy. That is: • The larger the dose (>50 units) of short-acting insulin, the longer the duration of action (53). Largerdosesofthehumaninsulinformulationalsoprovideaflatterprofile.This has not been found with the newer rapid analogues. (44,45). • Obesity at the injection site has been a controversial topic suggesting a slower absorption in the patient with a larger BMI. (53,54). Howeverthe obesity effect was not reported for glulisine, where the same pharmacokinetic and dynamic properties were noted regardless of obesity (55). Studies looking at the injection depth in normal weight and obese people using lispro insulin have found no difference in the pharmacokinetic and dynamic properties between the subjects using 5 versus 8 mm pen needles()