Transitions To, From Insulin Degludec Require Careful Follow-Up

By Will Boggs MD

January 06, 2020

NEW YORK (Reuters Health) - Transitions of patients to and from insulin degludec require close follow-up, including frequent adjustments of insulin doses, to avoid potential hypoglycemia, according to a new report.

"One can induce stacking of basal insulins if differences in pharmacokinetics/pharmacodynamics (PK/PD) are ignored," Dr. Boris Draznin of the University of Colorado Anschutz Medical Campus, in Aurora, told Reuters Health by email. "Knowledge of PK/PD is not a theoretical 'nuisance' but has tremendous practical implications."

Differences in PK/PD complicate transitions from one basal insulin to another. For example, insulin degludec, with a half-life of 25 hours, achieves steady-state concentrations after approximately four days of administration, whereas insulin glargine, with a half-life of approximately 12 hours, might never achieve steady-state concentrations with daily dosing.

Dr. Draznin and Dr. Irl B. Hirsch of the University of Washington School of Medicine, in Seattle, polled 200 diabetes care providers, soliciting their opinions as to how they would handle five clinical scenarios where patients were transitioned between insulin degludec and other forms of insulin (glargine, NPH, insulin pump). They received 30 detailed responses.

Dr. Hirsch said he was surprised by "the variability of the answers to the questions we asked."

The responses of endocrinologists revealed multiple approaches to these vignettes, as well as elements of confusion, the two researchers report in The Journal of Clinical Endocrinology and Metabolism.

In some scenarios, endocrinologists would directly substitute insulin glargine while insulin degludec was still on board, with a significant risk of hypoglycemia. Keeping the PK/PD of various insulins in mind while deciding on their dosing and timing should diminish this risk, Drs. Hirsch and Draznin write.

"In 2020 the world of basal insulin is much more complex, with each insulin being a bit different than the other, with degludec having the longest PK/PD," Dr. Hirsch told Reuters Health by email. "Between outpatient formulary changes, hospitalizations with degludec not on formulary, and transitioning to insulin pump therapy from degludec, clinicians need to be familiar with how to best transition for these various common situations."

"Patients' safety is the most important item, and frequent follow-up with necessary adjustments is the key to assure patients' safety," Dr. Draznin concluded.

SOURCE: The Journal of Clinical Endocrinology and Metabolism, online December 16, 2019.